Approached by a recruiter but lack confidence and have other issues

Don't know if I'm seeking advice per se or just want to type out my thoughts to help with processing them. So I apologise in advance if people read the thread and think "well that's 20 minutes of my life I'll never get back".

I'm currently in the 12th year of my second job, working in the IT department of a small manufacturer. It pays pretty poorly (£20k), way below the potential pay for my skill set if I may say so without sounding arrogant (I enjoy automation projects when they come up, e.g. writing little scripts to make things easier for people. Dedicated programming roles, for example, tend to command like twice that.)

I've been messaged by a recruiter on LinkedIn asking if I'd like more information about a job he's working on for a large company in the area doing desktop support. He only alluded to the company (as is normal) but I'm 99% sure I know what company he's alluding to and with it comes good career development prospects, decent pay, share scheme, etc. Without asking, I have a feeling they'd be paying at least 10k more (my current company would never dream of this).

Sounds like a no brainer right? Well I'm fretting about even responding to hear more and the feeling of obligation to carry it forward to application and interview, and leaning more towards saying thanks for thinking about me, I'm best off with stability for now but keep me in mind in the near future (when, if I put my mind to it, maybe I'll get my s*** together). Here's the thing, or several things:

• First and foremost, I'm deeply in a comfort zone at work and at home. Sure I'm not very well paid but as things stand it's enough, I don't really need to be, and past experience tells me that expenses simply find a way to expand to meet your salary anyway, like a gas in a vacuum. I have enough to live, have some leisure, save a small amount, and pay into a pension (reluctantly, so that I don't risk wanting to top myself at 70). People tend to pour scorn on the following hence the wall of justifications but... I still live with my parents. It's another comfort zone. They're happy to have me there (talked me out of it when I was last toying with the prospect of "maybe I should move out as it's the Done Thing in our society"), I like being around them, I share the costs and do my best not to be a burden, expect I'll probably be looking after them as they get elderly, and of course, it's much much easier than trying to live on my own. Mortgage is paid off etc. We have a driveway (a luxury I don't think many of my generation enjoy) so I can home charge my car etc. It's all one big ball of comfort.
• One could argue that with no real responsibilities I can take more of a risk, but in connection with the above, I don't want to ever burden my parents by treating them as a safety net.
• I have some sort of undiagnosed problem. One way it manifests itself is that I'm absolutely terrible at eye contact (it feels like same poles on a magnet to me), a must for things like job interviews. Somehow when I got this job I managed to wing it, but seem to have gotten worse rather than better over the years. I have a strong suspicion that I have some degree of autism, but have never got diagnosed (partly I don't want to know, partly I don't want to be labelled, partly I don't trust myself not to use it as a crutch). I think this also feeds into the comfort zone / familiar routine thing.
• My self confidence has nosedived over the past 12 years. In part this is a good argument for leaving as it's largely the workplace that has dragged me down (I work with one of those people who is always negative/contradictory when you try to have some input and just makes you feel inferior), but it also makes it difficult to countenance a situation, like applying for another job, going through probation if accepted etc, where self confidence is paramount. Heck, I'm plain terrified, all it is is a recruiter message (some people get loads) but it's all I can think about, lost sleep etc.
• I'm always tired (and with that comes poor motivation). Have spent my whole adult life failing to improve my sleep schedule etc but just never really got it right.
• A benefit of my current workplace: it's just down the road. Walking distance, if I could be bothered. The other place isn't far away by any stretch of the imagination, like 10 miles which the extra pay would well outweigh, but being able to roll out of bed and down the hill to work is nice.

The result of these issues is:

• I don't feel that I deserve anything better. In fact, I feel very lucky to be employed in the first place - normally people like me, with the grand list of personal flaws above, are some statistic or other. I think I'm fortunate in that in my current job we're a classic IT department straight out of The IT Crowd, just kind of left to our own devices in our 'lair' and called upon when someone needs help, so the bunch of flaws are less noticeable and more tolerated. I might be more "in plain sight" in some other job.
• I think I could improve if let's say I took this to heart as a "missed opportunity" and set my mind to self improvement, but it would take time. It'd certainly not be realistic to transform into a different person within the timeframe of a recriutment pre-selection process.
• If I went to interview at $big_company now (a major local employer who yes, it would be nice to work for if/when I sort myself out) then the present version of me is what they'd see and remember. As it's not very good, I fear that would damage my future chances there in the likely scenario that they detect my lack of confidence etc from a mile off and reject. This isn't a "once in a lifetime" opportunity, I'm sure others will come up there in the future, and I'd like to be fully mentally prepared and really get it together to at least leave a good impression. Not that it's easy, but I think even in my current job, I could work on the motivation issues, confidence, eye contact problem etc with a concerted effort.

So at the moment my draft response boils down to, I'm best off with stability for now but that the company I believe is being alluded to is one I'd be very happy to consider for similar roles at a later date if they'd like to keep me in mind and get in touch again next time. It's unsent, at the moment, while I think about whether I'm about to make a terrible mistake and whether I could in fact "fake it and make it" and am just kicking the can down the road.

Because this has made me seriously reflect though, I think I'm now freshly motivated towards self improvement to better "deserve" something like that (or even my existing job to be honest), but that it'll take time before I'm ready to present myself in front of an interviewer, prove myself in a new job, get to know a bunch of strange new people etc. Where to start, that's another question, but I feel a bit better for getting that off my chest in the first place so that's step 1.




Edit: 500th post. At least churning out textwalls on the internet is something I excel at.