Postpartum Sex

Okay, straight with me. Is sex different for you since your babies were born? It is difficult to find times when we have the opportunity and energy. Lately, it has been a little better as far as finding chances because our little guy is sleeping better. The thing is that my husband is fairly large and takes a while to finish and I have found that it is more difficult for me to get and stay self-lubricated. After a while, my body feels like it is literally pushing him out. It gets painful for me and we end up having to stop, which is frustrating us both...especially since we are hoping to start trying for baby #2. (Our first is a little over a year now.) Is this normal? Does it get better? Any suggestions?