considering abortion... please help

REPOST ( posted in general pregnancy bu5 was told to post here for more helpful advice even though everyone but a few was super helpful!) just looking for some advice from people who have been in a similar situation to me. so I have 3 kids already ages 5, 3 and just turned 1 and I didn't plan on anymore, I'm still breastfeeding my 1 year old and haven't had a period yet, we have used condoms everytime and as far as we are aware none of them broke but yet here I am 5 weeks pregnant... I'm absolutely terrified and will not cope with another baby for many reasons besides 3 young kids is hard enough! me and my partner aren't on the best of terms right now and another baby will definatley make things worse and I worry I'll become a single mother.. financially we are struggling as baby #3 was also a surprise but that was due to us being stupid and using the pull out method ONCE and she put a huge strain on our relationship and us financially and my health... I cannot have another baby:( I want an abortion but then when I think about what I'm doing I just can't even believe I'm considering it but on the other hand... it will ruin me and our family.. what do i do? EDIT also forgot to add carrying a baby will be very hard for me, I've had gestational diabetes during my pregnancies and will get it during this one, had SPD and extremely bad morning sickness so even though I'd love to chose adoption it's also my health is why I don't want to carry a baby.