Baby #3-Please dont judge

We currently have an almost 6yr old and a 9mo old. I found out we are unexpectedly, expecting baby #3 last month(currently 8.5 weeks) and all I have felt is fear. I haven't had one ounce of happiness about this and it makes me feel awful. Ive been really struggling with my mental health the last year and a half(my depression got worse during my last pregnancy and turned into PPD) and feel like Im struggling to take care of myself beyond my kids and I feel like I barely have the ability to enjoy my time with my family as is. I know that sounds horrible but thats the sad truth about mental illness and I have horrible mom guilt about it constantly. I cant help but wonder and worry if this pregnancy will break me. I just keep wondering if I should continue on with this pregnancy or not. Please don't judge or post rude comments. Im already struggling so much with this because, although Im prochoice its not something I ever thought I'd be open to and am still morally struggling with. We were being careful, unfortunately careful wasnt 100% effective this time.