Pregnant and falling back into depression

I had my first child at 17. Ended up a single parent and kicked ass while doing it. Built myself up got a good job, a nice place and a reliable car. Getting there I was diagnosed with depression because it was a tough road. I took meds for a short period to help and saw a therapist but have been off meds and feeling great for at least 2 years and managing just fine. My son is 11 now I have graduated from college, have a successful career and have been in a relationship for the last 2 years with the most amazing person I’ve ever met. I’m 28 and he is 22. He’s very mature for his age, more mature than 30+ year olds I grew up with. He wanted to get married and wanted to have children, in fact pushed for it. Now that I am pregnant (18 weeks) I am starting to freak out. I’m worried he’s not ready. He’s faithful and sweet to me but is not stepping up. He needs to buy a new car because he only has a old two seater and he’s procrastinating. We agreed he would stay home with the baby when I went back to work for a few months and start school at that point but now he doesn’t know if he can handle school part time and the baby... it is do-able as he watched me go to Work School and care for my son. To top it all off he takes me to Kays applies for a card and gets approved has me pick out a ring and says he will go back to get it but if I bring it up he tells me not to rush it. I am just starting to feel like he just talks a good talk and being pregnant makes me feel trapped. I’m worried that I’m falling into depression because I am starting to resent him am not communicating in a way that makes any difference to get through to him and feel really alone in this pregnancy. I just feel like he is so stagnant.. we have four months until our girl comes and I want to be excited about it. I want my baby girl but these hormones and feeling so distant from my Partner makes me want to just do this on my own. I don’t even want to get out of bed today. Not the worst problem I’ve ever dealt with but I just really wanted this to be an awesome experience and it’s almost halfway over and I am starting to feel miserable.