I’m not excited for my new pregnancy

I have 3.5 years old and a 10 months old and currently 9 weeks pregnant with with my third, this pregnancy was not planned, I wanted to take 5 years break until my two little ones grow up and I get to finish my degree and work... I wanted the break because I’m already exhausted and I feel down and depressed quit often, sometimes I feel like I’m a bad mom and with this pregnancy I feel I’ve been more angry and easily irritated, sometimes I yell especially at my oldest and i know that’s wrong and I feel bad and ashamed immediately, I feel bad that I’m not excited for this new baby the way I was with my other two, being a SAHM is very hard I know I’m lucky to get to spend all my time with my kids but it’s still very very hard I used to do more activities with the kids before getting pregnant, but now with my morning sickness I can’t and I’m always not in the mood I just feel terrible...

I can’t imagine how I will handle 3 under 4...

Any advice or thought are very appreciated