Most Helpful Guy
Your mind is going to find a way to sabotage your relationship if you don't start believing he likes you. You may leave him to avoid being dumped when it may never happen cause he actually likes you. You need to believe you're worthy of something/someone before you get it/them.
But another way of looking at this is that being a single guy sucks sometimes. Having to approach 50 or so girls before getting one that likes you, let alone one that you like is no fun. The stability of a relationship, having a girl you can regularly see is very appealing... if she's cool and not insecure. You may want to work on that part.
Most Helpful Girl
I feel like i've been in this situation. It was incredibly hard to deal with, mainly because he wasn't the nicest person and used my insecurities against me in regards to how I looked. I would give him the benefit of the doubt for now, but I get how it can be difficult.