In a dilemma...

So my husband and I have a one year old daughter (17 months) and a lot of people around us have been having more kids. While we were dating I initially wanted 3 kids, he wanted 2 so we compromised and decided on 2. Now after having our little girl (who is amazing btw) I don't think I could handle another one. I had a extremely traumatic birth, ending up getting ppd from it and going to see a therapist/take antidepressants. The thought of going through that again scares me to death.

If I had it my way I would get my tubes tied, etc to prevent future pregnancies. Yet, my husband has been giving hints he's ready for another. Talking about what it would be like if we had a boy, how our daughter would be as a big sister. Also, obviously no one is obligated to help us, but we don't have support from family either. So the thought of me trying to take care of 2 kids while he works all day is more than I can handle mentally. After our daughter was born I told him this and I think he just thought it was my nerves because I had just given birth, but I still feel this way.

I'm afraid of what this will do to my marriage, because I know this will break his heart. I feel horrible. Advice?