Idk what to do…

So it all started when i met this guy when i was 14. He used to like me so he asked me to be his gf, i rejected him because i was young and i felt that i wasn’t ready for a relationship, plus i wasn’t sure about my for feelings him. Months later,he moved out to another city far away from where i live so, sadly,we lost communication. Years later, I’m 21 now. I accidentally found him on Facebook so i decided to messaged him, we talked he was really sweet and told me he still have feelings for me so we both agreed on meeting each other again. We met and he confessed again and this time i told him yes. But that’s when things went downwards. He used to text me everyday now he only texts me once a week, he never invites me anywhere and when he’s with me he tells me he’s bored and leaves to hang out with his friends. I notice that when there are people around he doesn’t hug me or sits beside supposedly because he’s shy. One day he says he loves me and doesn’t want me to leave and the other he’s desperate to leave. The thing that bothers me is that he was leaving 2 days after and we weren’t going to see each other until November of this year. So i thought he was going to spend time with me but instead he went out with his friend and didn’t invite me but picked up this one girl to go with him to the place they were going. I confronted him about it the next day but he told me that he was so stressed he forgot to invite me and about the girl that it was just his friend and to stop being so jealous. I don’t know what to do to be honest, i love him and everyone tells me he’s not serious about me that i should find someone else but i can’t get him out of my head now.