abortion booked but unsure I want to go ahead

Hi, I have a 7 year old a 10 month old and I am now 5 weeks pregnant, me and my partner split 3 weeks ago and I found I was pregnant 3 days later. It's been an emotionally abusive and some time physically abusive relationship but I miss him and him me. It can't go on. Now I know I won't be able to cope alone with an extra child or even the pregnancy as I get so sick  while pregnant. I feel like my 7 year old will suffer as he doesn't get to go places as it is while my daughter goes to bed at 6pm every night. I have lots of support from his and my family but I want to start uni in September but baby will be due oct 1st. But can't face the guilt of abortion. I know when it's done it will haunt me forever.