First time poster here.
Me and my friend have known each other years. In some ways our lives are similar. Mainly our childrens ages and we got friendly as both single parents. Recently I have started to pull away at how our lives are changing. This isnt to be spiteful far from it i am happy she is. But by the same brush my life is hard and i am unhappy.
My ex was nasty. Hers also wasnt great. We carried on with our kids however one of mine has a life threatening illness and the other has a physical disability. Hers has some mild special needs but these are genuinely minor. Am not minimising so please no posts about invisible disabilities as im not like that and helped her over the yrs as she has me.
She has since met a lovely man and physically is looking amazing. They both have their parents who are generous and they have lovely holidays and on facebook look perfect. I get this is only a snapshot but they are all very happy. She also has loads of friends and is very keen that people think good of her as in she presents herself in a certain way.
My parents are both dead. We have no contact with ex as social services would become involved if we did. I have had to quit work due to caring responsibilities. I have no time or money to look nice. I have a severe and enduring mental illness and a physical condition causing pain.
I am pulling back because the more I see her life the more depressed i feel. I will never get another partner first because i believe im worthless after ex. Second due to the strain of kids and my own conditions.
The thing upsetting me is that anytime i try and talk through my problems (very rare) hers are always worse. Her negative experiences are always worse than mine similarly her childs needs are more worse even though there have been 4 surgeries this year alone on my DD. Everyone thinks shes an angel for coping. Her childhood was worse than mine she was more battered than me in marriage. The reason she has not got a mental illness is because she thinks positive. Her achievements are made out to be the same as mine so for instance i would get a degree and her a gcse (example). But she would tell everyone and put it on fb about what shes qchieved despite adversity and how hard her life is. Its draining. I feel anything nice about my like is minimised and any acheivements are invalidated as they arent hers.
If i make friends, she makes friends with them too and then it is always about her being over bearing and all these hard things she has overcome and said friends are totally inspired. I on the otherhand pull away or it is all about my friend and how great she is. I now keep any friends secret or mention them under pseudonyms so she cant steal them. I must sound about 12.
I struggle to get through each day. Many times she has helped me out. But I am starting to resent this as she comes across so smug (to me) and i feel irritated by it. I might be bad for feeling this but i do and i have withdrawn a lot. Then according to her i am ungrateful and think im too good for her.
I honestly feel so shit when i see her and hear her talking about the next holiday or anything. I cannot understand why anyone would want me but she is so sure she is attractive that she demands respect. She has made the most of herself since being married and looks lovely. I am sure this is the right way to be.
But like another poster asked i would probably erase myself from life. I am already doing it anyway (not suicidal but no point if friends are going to be taken off me-i now spend every day alone or with my kids). She criticises my parenting. It should be her way or no way.
What can i do to feel better? I am happy shes happy but its making me feel worse. I dont want to feel like it 
Why are some peoples lives so much nicer than others? I know im lucky to have a home and car and to have kids. To someone else i have a perfect life i suppose so maybe i am just depressed.
So AIBU to feel like this and what can i do about it?