Pregnant and a toddler

I have been feeling like the worst person/mom ever the fast few weeks. When I am pregnant I have issues with depression and anxiety. When I was pregnant with my daughter it was hardest on my husband but I didn't have anyone else to take care of so I could just be lazy and sulk. Now I'm 28 weeks pregnant and I have 16 month old. I have been struggling to keep my cool and I have been so down and being bigger now it's harder and harder to do things. I feel like such a complainer! I love my daughter so much but I'm a stay at home mom and my husband works alot so it's just me and her most of the time and I never get a break. I have no one else who can help out. She is at the terrible 2 stage and I feel like all I do is tell her no and get frustrated with her. I don't want her to be an undisciplined brat but I don't want to constantly be yelling at her either. I just feel like no matter what, I'm doing everything wrong, I feel so guilty all the time. To make things worse I can't help but feel like things would be so much better and my daughter would be so much happier if I didn't get pregnant again. That's makes me feel so ugly, for the longest time I wasn't sure if I would ever be able to have a baby and now I've been blessed for a second time and I just complain and can't seem to get excited. I just want this to be over already so I can feel like myself again and be a better mom.