Stressed and worried! Please Help!

Hi everyone,
Im new to this site and id like to know if anyones knows whats happening to me?
Right, here goes....
Im female, 22. My dad Committed Suicide 3 years ago and since then and have lost 3 other members of my family/friends, all were horrible deaths.
Although i feel like im moving on i feel parts of me are not.
I worry about the stupidest things, and worry about them to the point that i dont eat, although i want to eat i just cant seem to. At present i havnt eaten for 4 days. I mainly worry about my partner, 'does he love me' 'is he looking at porn at work' 'is he chatting to girls' 'does he still find me attractive'. And although i have been with him for 8 years (since i was 14) and he has made some real life changes to keep me happy, i still panic everyday about what hes doing. He very openly told me the other day something personal that he used to do that all men do in there lives and it really threw me. I just couldnt get my head round it, i cried about it for days. I never used to be like this. He loves me so much and i love him so why am i not happy, and terrified of him looking at other girls. I stress about my mum loads as well, shes been through so much these last few years i wish i could take all the pain away but i cant, i cant let it go more than a week without seeing her as i worry she may be upset.
I think really bad thoughts about myself and other people and it doesnt seem normal to me. I can honestly say i dont how im feeling right now, Just lost.
Thanks for reading
Katx