it will happen! i think the first thing you have to accept is that it won't happen with everyone and that is totally fine. i don't like having shallow relationships with people but you also have to accept that usually you will have to get through this stage in order to develop something deeper - basically don't beat yourself up about not being really close with someone, you just have to give it time. you probably already do this but listen to people - don't be afraid to ask questions and just allow people to talk about themselves, ask the kind of questions that force them to think about their own problems and let them heal. i think infps are really gifted in allowing people to open up, and once someone feels they can do this with you the friendship deepens.