Really need advice re: Mental Health and weight insecurity

Hi ladies,

I don't really know where to direct this so if this isn't the right spot, hopefully you can help me find one. I'm almost 21 weeks pregnant. This is our 5th baby (1st girl). It was a surprise...but a happy surprise nonetheless. However, I'm struggling mentally. I have an OB check up on Friday and need help with how to bring this up to my doctor. I have A LOT going on in my life right now. I work a full time job M-F 8:30-5:30 and my husband works 60+ hours a week. I'm also in school full time (online). My oldest son is special needs (autism/adhd) and we are having to get our 5 year old tested for learning disabilities per the recommendationof his teacher. On top of all this, my grandmother has fallen ill and wants me to take care of her finances, help with her arrangements for when the time comes, etc. I'm also having more put on me at work because of lazy coworkers. I have a desk job but its still mentally exhausting. Lastly, I am struggling with everything I eat. I'm obsessed with the calories, carbs, etc and terrified I will gain back all of the weight I lost pre-pregnancy. I am definitely trying to make sure I have a healthy baby, which is why I want to talk to my doctor. But with all of this, I don't know how to really bring it up. Its becoming a daily struggle for me. Its all I can do to get up in the mornings. I can't sleep at night and when I get home from work, I go straight to the kitchen to make dinner, check the kids homework and get them to bed and all I really want to do is lay in my bed and sleep. Please no hate. I genuinely want a healthy pregnancy and have never dealt with any sort of mood disorder or anything while pregnant.