BPD ruined my relationship with J...

I'm an English teacher in Japan and my school employs two English teachers. Last year I was paired with a 24 year old Australian guy who was immature, aloof and condescending...so much for making friends at work. Then in April he left and I got a new partner, J. From the start J was extremely friendly and laid back and kind... what a change! I was surprised by his continual kindness. Like many of us I've never really had a lot of close friendships or people I can talk to on a regular basis, so I was over the moon when J would every week ask me how my weekend was... no one's really taken a genuine interest in my life like that before. We became fast friends. I was open to him about my issues and he was kind and concerned and patient when I was feeling bad.

And of course I fell in love with him. I know I have a tendency to fall in love too fast so I wouldn't even admit to myself that I loved him until I was really sure. But I was really sure. And to my surprise he seemed to like me too! One night we were out drinking and ended up flirting and cuddling a lot...then he stopped me and told me he wanted to just be friends. I started crying then kissed him (my favorite manipulative tricks) and we ended up going back to his place and sleeping together. The next morning he was remorseful and again said he just wanted to be friends but I didn't feel sad because I knew I still had a chance. Nothing really changed and we still kind of acted like a couple - went to the beach together, went to the movies together. Then one day he said to me "I know we've been hanging out a lot lately just the two of us, but is it ok if we just stay friends?" This time it sunk in. We weren't going to get together. And now I started to go crazy.

I started to get depressed all the time, and then call J looking for help, then get mad at him for not responding the right way. At the time it really seemed like justified anger - he wasn't giving my crises enough attention. But when a friend pointed out that I was creating crises because I wanted an excuse to talk to him, it made so much sense. Naturally J got very stressed and disillusioned with me. In November he started dating a Japanese girl and I was devastated. I started sending him crazy melodramatic emails about how devastated I was. At the same time I got dumped by most of my friends because of how depressed I was and how I was lashing out at everyone. Hitting rock bottom forced me to start taking care of my mental health more - found a new therapist, read some books. The last day of work before Christmas break J told me I was doing well. He split up with his Japanese girlfriend in January and our friendship started to improve.

But unfortunately our one year contract is up. Next Tuesday is our last day working at that school. I'm really dreading being separated from him. I don't have a lot of friends so it's been wonderful having someone I could talk to at work three days a week. Of course any kind of abandonment or separation really freaks me out. I know I'm going to get really insecure because J is a very important friend to me but we won't be talking to each other as much as before. He already kind of keeps me at arms' length. He's hypersensitive to any kind of talk about my feelings or psychology stuff. He's a bit of an avoidant himself...he's very kind so he gets too caught up in other people's problems so he likes to be alone. He keeps telling me I need to learn to be on my own, and he's not wrong, but I wish he understood that I need relationships too. I can't be the lone wolf he is. He knows I idealize him and says I need to stop idealizing people. But I do truly care about him too. I wish there was some way I could regain his trust, and show him that I'm making changes. It's so hard being pushed away when I reach out to him.

I'm wondering what can I do to end this year in a positive way? Of course I want to talk to him about my fears, about my regrets that our friendship has gotten sour. I also want to tell him that it's not just idealization, I do really value his friendship and really care about him. I really want him to still be a part of my life. I gave him a graduation present yesterday (a sketchbook because he likes to draw, and Oreos because I know that's his favorite). I want to write him a letter too, telling him how much I appreciate everything he's done for me. What should I do on our last day together on Tuesday?

sorry that this turned into a novel (>_<