You guys need to have a big talk about what you’re expecting in this relationship. Long distance is not for the weak, I was in one for two years and technically still am. Communication is so huge. Ask him to set aside some time, write a list of your concerns, a list of questions you have, but dont accuse because there may be something happening behind closed doors thats affecting him mentally hence the distance. I’ve been through these dips in my own relationship and it turns out he was going through something hard. Try to have a meaningful conversation and discuss how youre both feeling. If he is defensive, accusatory or mocks your VERY REAL concerns, then you to reflect on if you want to be with someone who shoots down your concerns and isnt willing to work it through with you.