Relationship

So, I've been in a really good relationship for 6 months now, almost 7. This is my first serious relationship, and I'm absolutely in love with him. My parents love him and look at him as their own. The thing is schools starting up soon and I'm scared that he'll lose feelings for me when school starts up. I'm one to think alot about my future, and it gets in the way and always brings me down because I always get scared of losing him. I'm young, so I know there could be a chance we don't last forever (I really hope we do though). He always says he won't leave me ever. But, he's lied to me a few times, the most recent was sunday. And I have trust issues so its been a little hard to trust him, but I'm getting there. I'm just so scared of losing him. And I don't know how to ease it. Do you guys have any advice or such? And I'm sorry its so long.