Firstly, besides answering relationship questions, I also assist clients with legal issues.
Essentially, you could take your friend to small claims court in an effort to recoup the monies you lent him. As long as you did not stipulate the funds as a gift, you could still receive a court decision ordering him to pay you back.
Although you are legally within your rights to pursue a small claims court case, the real issue that needs to be discerned is if there is potential to have a frank, open conversation with this man to place your sentiments and feelings on the table. If you do not at least make the attempt, you will of course have feelings of self doubt and no closure. You know what they say Rick,-- "Nothing ventured, nothing gained!" You have already mentioned that you date, but continually compare your friend to your dates, so why not write your friend a note explaining that you desperately need to speak to him. Let him know to call you and then arrange a meeting in which you lay your feelings on the table.
What is important in this situation is that the focus of the conversation should be steered by your feelings of love first and foremost. You could also express your concern for his not being clean and sober. As important as it is to address that he may indeed be engaged in active addiction, it would be best to avoid bringing that up straight away. You need clearly express your feelings and love first and then once you know where you stand, broach the subject of alcohol use. Focusing on this addiction would overshadow the importance of your feelings. You want that issue to be clear when you speak to him. He could feel threatened by your past association as his AA sponsor, nothing would be gained by mixing the two issues.
There are no guarantees as to how this will develop, but at least you will have the comfort of knowing you tried. If by chance, his feelings are unfortunately not mutual, then you can clearly address the issue of the monies owed and more importantly move on to a healthy relationship with another man that returns your love.
Should you have further questions or concerns, please do not hesitate to ask. I will check back.