Hi first of all could you take some time even in the kitchen or something to have a cup of tea for 5 minutes really does sound like you could use it.
My mum has twins and even thogh they were little angels just the fact there is 2 makes it seem hard enough never mind when they cried.
My DS was a little terror as a baby sounds like your twins, the only thing that seemed to help was a walk in the pram, might sound obvious but really was one of few things that worked.
Walks in the pram, if your really desperate and it sounds awful but the CBeebies CD or the channel the colours used to amaze him for 10 minutes and his play gym he loved that I got one with a moving bird thing on it that was a godsend too. Oh and baby massage!!! Cannot recommend that highly enough I attended the class with my mum when I was pg to help with the twins (8 months of a difference between them and DS) and they loved it as did DS.
Could you get a friend or family member to go with you to one of these? They are normally free through your HV will have details, if no friends etc can help the leader might use one of them to demonstrate techniques leaving you to concentrate on one, they lasted 4 weeks with us and my mum and I used to switch babies every week so they both got the benefit of mum doing it.
How many times have you seen the doctor? Does not sound right that he is so dismissive. I would contact your HV and ask them there is clearly a problem could just be colic or wind or something but still you need your sanity too!
Trya dn get a few hours off to yourself even once a week worked wonders for me just getting out to see my friends, mum or just chilling in teh bath with a book was great and don't forget it's early days yet things will get better!