Scared

My boyfriend and I just found out we're expecting again when I had a copper IUD. We are in a commited relationship of 5 almost 6 years and life just kinda got in the way of engagement and the wedding. We have a 15 month old and right after having him my boyfriend lost his job where he made really good money.  So his parents begged for us to move back in with them and we did. Fast forward to now and he has a new job where he makes good money but ite because he will make quarterly bonuses that adds about 20,000 extra a year but until then we make about 31,000. Which isn't much to live off of.  We are now waiting on a apartment to move in and finally started to get our little family together and now we're pregnant again which don't get me wrong I'm excited I'm just terrified that we're going to struggle financially.