Driving myself crazy

I never thought it would be like this. I always wanted my first child to be my partners first child but it didn't work like that. Im a step mom to a child that I love and he loves me . I find myself wanting to do things that probably aren't appropriate because I'm not his mom. His 2nd birthday is next month and I just want to throw him a birthday party and spoil him but who am to call those shots ? He calls me mom and he doesn't know any better right now but I don't want people who knows the situation to think nothing of it but I do everything a mom would do, sometimes more than his mom does and it doesn't make it any better that we've been TTC and haven't had any success yet, its making me really sad. Then my friend who knows I've been TTC comes and shows me her positive pregnancy test. I don't want to act like I'm not happy for her but I could really care less right now. Hopefully I get my bfp cause I'm bout ready to give up.