Pregnancy depression

I’m desperate to talk to someone. I'm 3 months pregnant and things are really getting on top of me, especially work. I feel like I'm being given to much work to do, but when I talked to my boss I realized it wasn't just me finding it hard to cope. She has given me a couple of days off work and I've got a doctor’s appointment on Thursday. Being single, I worry about money, having a baby and getting work done. What can I do to stop worrying too much?