No Pinky, you are not delusional . Your parents used you to feel better about themselves. This is their fault (due to their own problems), not yours, and you have nothing to feel guilty about.
Your problems sound just as bad as anyone's on here IMHO.
So many people say the same things don't they! - the self doubt - am I going mad, was it really that bad, am I stupid to have let it affect my life when my family members think it was nothing and I'm overreacting/oversensitive etc
- and the feeling of unworthiness - I don't deserve help, other people have suffered more, perhaps I'm being oversensitive or weak, perhaps 'they' did nothing wrong and I am being unfairly angry with them.
The fact that so many of us have said these things makes me think we are not going mad, lots of other people feel like this too, and they have had similar problems in their childhoods eg overcontrolling/critical/unloving/cold/selfish/neglectful/abusive (physically, sexually or emotionally) family members.
The more people come out and tell their stories on this thread, the more people who read it feel that maybe they could find the courage to tell their story too. And admitting to yourself what happened and acknowledging to yourself how you feel about it rather than trying to push the feelings down because you are ashamed of them is the first step to feeling better. Keeping your feelings pushed down makes you ill eg with depression, but other physical symptoms too quite often.
The people who have made us feel crap would like us to think we were oversensitive and overreacting and that what they did wasn't that bad because then they don't have to face up to their guilt or their failings and deficiencies. I wonder if I would ever be brave enough if my mum says ever again "you are sensitive and you think too much, you always did", to say "That's what you would like me to think but I'm not going to take the blame for how you all made me feel".
The people who hurt us are shit people with shit opinions and we should try hard not to believe their opinions! The reason we do believe them and feel crap about ourselves is not our fault, it is because when you are a child you naturally believe what your parents and older siblings tell you. Your brain is building itself at that stage so what they say gets built in and is then hard to get rid of in adult life when you know logically that what they said is wrong!
Our self doubt comes from the crap 'care' we received as children.
Our parents are supposed to teach us how to be positive and feel good about ourselves and cope in the real world and how to learn to be happy without hurting others etc. If you feel the opposite of these things and it isn't just because of events that have taken place in your adult life then your parents did a shit job. You are allowed to feel angry with them for that. It doesn't matter if you weren't shouted at/hit/sexually abused as much as some other people, they still did a shit job and you deserved more, as every child does, so you are allowed to feel angry. Even if you can see that your parents had problems of their own which caused them to be rubbish parents and you feel sorry for them or maybe love them it is still ok to feel angry with them at the same time!
A child deserves to feel loved, looked after and protected and to be gradually taught how to be a happy independent adult. I can't think that anyone would disagree with that. If you didn't feel those things, to the extent that you feel unhappy as an adult, then your parents did a shit job. (Must remember to live up to my own standards as a parent myself that I criticise my parents for not meeting!)