Need advice rather upset by response

Hello MSE im new here but have browsed on here for many years now.
I recently was in a accident that wasn't my fault, Other insurer admitted fault & my car was written off as the crash bar was damaged and bumper was cracked and ruined ( was a older car never the less still our trusty car! )

I was going round a round-about when my vehcile was struck at a unknown speed the bang and force was enough scare me out of my skin! which also caused my car from turning from right to facing left! due to the seat belt hugging over my right shoulder being the driver it didnt stop me from being slinged to the left sideways! I am a anxious person at the best of times, I was in shock and was sure the impact must been around 15mph due to the damaged to the third party car which included a front light fallen out, front bumper competely cracked and hanging off with the front wing pushed under the bonnet.
At the time i was in shock and tried to call the police as the young man was in a car full of lads with one female who ran away immerdately at the scene, The police didnt attend as he gave me his name number and insurance. Next day i wake up in agongy and im usually as tough as nails, splitting headache coming from my shoulders up and my lower back in spasms, I rang my gp who at the time just advised paracentomol and iburofen, shortly after i was struggling to sleep due to my back spasms and my left foot that kept going numb which has now resolved. which included me to getting up at 3am and giving up on the dream of sleep.I demanded to be seen by my GP who checked me out who confirmed i had whiplash which i already knew, she then proceed to check my back and made me bend over i got to maybe 35 degree angle and she grabbed me and told me not to do that again were i was told i have get physio... Unfortantly im not a rich man and cant afford that so i rang up the insurer who informs me one of my legal expense solictors will be in touch about injury! Sure enough i got physio, after 4 sessions i was sent away and told to contact my doctor again to get something to relax the nerves and calm the pain as she couldnt do anything due to the spasms in my back, SO i was given getapenlin? i think it called and diazepam which helped! WIN! I was on the mend, Now wre are at the bit were im pee'd off and confused! Upset aswell along with now my ex-partner who had to watch me suffer! Couldn't even lift my son up or carry large amounts! Ive turned into a yo-yo sit too long back hurts - stand too long back hurts.... I have gone through pain last couple of weeks not life changing forever but temporarily! Luckily im better now and my physiotherpist thinks i should start coming off the meds and start trying to do more on hand tasks.

They have raised a Low Velocity impact saying they intend on fighting saying they no way i could of got injured!!
The 3rd party was a young male i believe 19 who only passed his test 2 months ago! I know he repaired his own damaged to his car and hasn't been in for repair as he told me himself and his dad a mechanic who will fix it & even plead me to let his dad fix our car.
I have got pictures of his car with the damage and with mine being written off too! But they are sending a engineer to look at both cars... i have scine seen his car going around repaired.

It is stressing me out as it sounds like they are making out i am lying about injuries that has hurt! ive had to take drugs and some physiotherpist punching my back for 12 sessions to get it to stop having spasms alot with the neck pain!
My solictior always busy and wasnt reassuring just said they are raised all the time now but doesn't fill me with confidence and i dont want to be left with expensive bill for something that i shouldn't of had if someone was just watching were he was going rather than showing off to his mates and a lass who ran off! His actions didnt seem to impress the young lady.

I will add other side not recieved any pictures of my solictor yet- medicals - physio report etc! So they jumped on this denying injury before anything even been forward to them!