How to get over him

Over the summer I did an activity where I saw this guy four hours for five days a week. I fell for him hard. However, I was 19 and he was 29, but I didn't care. We decided to date, but we only lasted 10 days since he was going through some severe emotional problems. Yet, we remained friends. We got pretty close again, but then I had to start school and work and began not seeing him as often. He stopped texting me even though we had been texting everyday. I made effort to see him and we never spoke when we saw each other. I decided to send him a goodbye text since things seemed to be going downhill. He said he still wanted to be my friend, but he was now busy with school. I was an emotional wreck while texting him since I had been talking to him so much and now nothing. Should I call and apologize for being so dramatic? Should I leave him alone? How do I get over a guy I thought I would marry? I know the busy thing is a lame excuse so is he really not interested anymore? Is our age gap a big part of this?