It's probably tough, I remember being 15/16 but here's what I think.

1) Should I get over him

Yes. Your life will go on, you have all of the rest of high school and college and the years after that to meet new people.

2) Is there a chance he still loves me?

Yes, but it doesn't really matter. If he is consistently lying and acting manipulative there are healthier ways to spend your time.

3) How do I make him interested in me

I don't have a great answer for this one, but I can tell you that 16 year old me had no idea what was going on or what I wanted. His mind (and yours) will change a lot over the next few years. I would spend more time thinking about what your priorities are, pursue those things.

4) How do I re-spark the passion?

There probably wasn't very much anyway. When I was younger like you I thought I knew a lot about what passion and love were, or what they were supposed to be. I'm 23 now and I can tell you that I was incredible wrong about those things. When I was young, the things I felt on a regular basis seemed much more extreme and important than they actually turned out to be.

What do I do?

I think you should be grateful for the few months that you dated and that you had a fun experience. I think that you should look forward to the next one and move on.

Good luck, in a few years you will look back and things will seem very different to you then.