Nervous. Scared. Worried

I cannot help but be so nervous about having a second, I feel so guilty since my first will barely be 2 years old before the baby gets here. He will be cut so short of being a only child and I can't help but feel awful about it. I also feel awful since my boyfriend and I were planning on get engaged and getting married like we wanted to but life just keeps getting in the way. 
I'm also so worried about how this is all going to work out since my boyfriend just took a lower salary to be home more and now we're expecting again and don't know how this will work financially. I know all children need is love food and shelter but I wanna be able to buy them that new toy they wanted or be able and take them on vacations. 
I do get excited about this baby but then my mind is flooded again with scared and nervous emotions. 
This just wasn't the expected and  isn't the best time to find myself pregnant again especially since I had the implant in my arm after my son was born. 
I just wish I was more excited.  :/