Gone But Not Forgotten

I was going out with "Sir" for a couple months and we had argued & broken up and gotten back together. Our status was a bit hazy as we were going to be strictly platonic friends but went back to a boyfriend-girlfriend relationship dynamic. We would communicate a minimum of 2-3 times weekly at worst. And see each other once or twice every 2 weeks. (Although we would go out relatively infrequently, when we did meet up I found it exhilirating and intense and it would be like 3-casual-dates-in-one for 5, 8, 12+ hours or include a sleep -over at one of our places)
Then I went on a trip for 2 weeks, and after returning, received considerably less contact - maybe two emails a week at most.
I missed him and wanted to meet up and he said he also wanted to meet up. I asked to see him a couple of times and each time he had something already planned to do. Then he asked me out to see a movie but I couldn't go. Next, he asked me to call him, and I did, (3 times in a week) and each time he 'wasn't there'.
We communicated via friendly email several times thereafter, however, when I pointedly asked him if he wanted to meet up on a specific date, I never received a reply.
I sent him another email a week later asking what was going on, with no response given. This was in April. The last time I had seen him in person was at the end of February. Sometime in July, I broke down and sent him a long rambling email begging for an explaination, telling him how much I missed him, etc. etc. (All the shameless mushy garble I would NEVER suggest any of my friends write to their crummy exes.) So it's October, almost a year later from when we first met, and I am so frustrated with myself for not getting over "Sir" and still miss him tremendously.
In all my other relationships, I had never fell so hardly for a guy. And I've told myself over & over to move on, but I'm also ridiculously frustrated with the fact there was no closure for me.