How to keep your man interested

My boyfriend and I started dating this year in March. We lived in two different states. Him in Arizona and I was in Utah. I was always worried he would cheat or find other girls but... he would constantly text and call me and video chat even when he was out with his friends. It made me feel like he was very trust worthy. I came down to Arizona on vacation to visit him when him and his family talked me into moving down. I've been living with him for 5 months now. Things have been going really well. We've had a few slip ups like me being insecure, he has some anger issues. But we've been a really good strong team. Lately I sort of feel like he's lost some interest. I've been trying to make friends and do my own thing but it's been really hard because I left all of my friends and family in a different state... on top of that... he told me he wants to marry me. I do see myself with him forever. But is 5 months too early for engagement?? We've known each other for years... but only been dating for 5 months. Also, Any suggestions on how to keep your man interested and how to do your own thing so you don't annoy your SO ?