Help with TTC

Okay so my husband and I stopped using any protection when we got married. It has now been a year and we are having trouble conceiving. We have a son (me)  but it was from a previous relationship. He's gone to the urologist and had an exam and now all he has to do his give his samples to the lab (which he's not wanting to do now 🙄). He wants to wait atleast 2 years before we have another (he honestly doesn't want anymore children, he tells me Asher is all he needs. But I feel like if I was to get pregnant he'd change his mind). But I feel like it's all my fault, I gained 45 pounds when I got pregnant and it has stuck around. I've read articles that being "overweight" could cause infertility.