Sky - leave or stay

Here is my dilemma. I just don't know what a "good deal" is anymore. I have been with Sky for 11 years. They caught me in the "10 month deal/12 month contract" trap this year (silly of me I know...i just didn't realise that this is what I had done) which means that my bills will go up to £50.60 in January and February until my contract ends. I have rung them several times to haggle (yes I used the guide) and they will give me a new deal for £37.60 which is £10 more than I pay now. Should I be grateful and go with it? I am only getting the basic TV package (no HD, box sets etc etc), standard broadband (no fibre), landline and pay as you go calls. They want me to commit for 18 months. I rely on catch up, record and the variety of channels so have looked around but have not found any other provider that I could honestly trust to switch to as other service providers are renown for having a bad reception in my area so I would worry especially if the TV is relying on broadband services. Oh and I only get 19 freeview channels so that one is not an option either. I have been OK with Sky and their broadband in the past so I suppose I know it works. So I am basically trying to put my mind at rest that this is indeed a good deal and if it is not what I can do to change it. One other thought was to request to cancel the contract for end of Feb and hope that they will call me before the 1st of January (when the big bill starts) to arrange a better deal to tempt me to stay...or have I just been spoilt with my last deal and I am now not appreciating what they are offering me? I am completely out of my depth with this one for varies reasons so any advice would be greatly appreciated especially as 18 month is a long time to commit to if you are not sure that you are indeed getting a good deal...which I hope I am to be honest! Thank you for your help!