I’m in love and I need help

I met an amazing man 6 months ago he suffers from a lot of mental health issues which is something I never wanted to deal with. So I immediately boxed him in as a fling nothing serious but I’ve fallen in love with him. He is so sure of me, he has introduced me to his family & friends and invited me to all his milestones (I.e graduation) and sees a future with me. And I haven’t done any of these things he’s never met my friends but the only thing I’m sure of is that I love him but idk why it’s so hard for me to let him into my world the way he does to me.