I purged only once, back when I was first starting out. Even though I only pitched some lousy Depends at the time, I still remember the feeling; hot, ashamed, embarrassed and wasteful, they may have been crummy diapers, but I spent money on those and there I was pitching them away like they were nothing.
You'll likely get responses from others who have dealt with purging more frequently than I, but I know from hearing stories that this can be a very persistent and annoying part of being an AB.
I found that when I bought primo diapers and AB clothes and all the other accessories for the first time, that I didn't have any inclination towards tossing anything like I did with the Depends years prior... maybe I had more self-acceptance than some at that time.
At the end of the day, the only real way to conquer the purge is to realize that this is always going to be a part of you (sounds like you're pretty much there on this point), accept that there's nothing wrong with being an AB and continue buying and adding to your stash... when you can of course, you don't want to start binging either, best to find a happy medium.
The more you buy, use, embrace, the easier it will become and the less you'll want to purge. Also, getting your own place helps too, I have had friends who never really conquered the binge/purge cycle until they had a place of their own and the extra privacy and confidence that came with it.
I think it's definitely in your best interest, anyones best interest really to just keep at it and try to overcome this, soon you'll fully accept this side of yourself more and you won't be wasting money only to purge your items. AB diapers and clothes are expensive and wonderful, you don't want to toss that stuff away
Best of luck to you