Firstly, a great big
so sorry to hear how badly you're suffering, both from HMS effects and from inconsiderate medical bods!
I think you're doing the best thing possible to help you manage - by getting involved in this here forum, you'll be able to become your own expert & find all the support & advice you need right here.
I'm kind of in the same place as you at the moment, having llost almost all my mobility over the last 6 months or so, and I'm 43, but I can't imagine how much harder that is as an 18 year-old who in the eyes of the world should be carefree and fit as a fiddle....
hopefully you have family, and a group of good mates you can lean on (literally I suspect some days!) and there's always a friendly ear here. Read up as much as you can, and keep pestering politely down at your GP's. there's a great thread here somewhere on how to be assertive with your doctor. you have a right to good care; you have a condition which needs managing, not ignoring!
I would also advise you to get in contact with your local social services, and ask for a home care asessment. if you are struggling with personal care, and managing stairs etc, there is lots of help available through them; I've got extra grab-rails & stair handrail fitted, and there are all sorts of gadgets which can help you keep some measure of independence. It might also be worth while applying for Disability Living Allowance; if you do, make sure you answer the questions as if it's your worst day; it can help to ask somebody who sees you on a daily basis & whom you trust to help you be completely honest with yourself; I'm in the process of this at the moment, and to be honest finding it really hard to accept just how limited my life has become; it's taken me 4 months to stop crying every day and come to terms with using a wheelchair every time I leave the house.
There are still plenty of tears, but I've decided I have to face this challenge; I have no choice, I'm still me, I still have a life and loved ones, it's just a different road to the one I thought I was on, i've decided to embrace the new challenge and use it to help others.
Love & hugs, hope you're able to smile thro the tears, take care