Placing a three month old for adoption

So I don't know how to go about explaining this but I want to place my baby for adoption. I love her to death but I don't know how else I will be able to do this. I am mentally unstable and I don't feel like putting her though foster care like I had to do. I thought I was better. I'm not. She needs a better family. I'm sure this is probably a stretch but I was wondering if anyone else has gone through placing their children for adoption (when they've been taking care of them already) or have lost their kids. Thanks. Also if you say "you shouldn't have kids to begin with" I will report you for being dumb and stating the obvious as if I didn't already know.

Thanks everyone for the support. Unfortunately I do not have any family or even friends to look after her. I've already been in contact with an adoption agency so I'll go from there. Thanks again.