I think your last statement may say it best. Fear keeps many people from doing things to get healthy. Fear of some sort of inadequacy in ourselves, that others may find out. Fear we can't get better. Fear we really are just bad. Etc. Etc.
This fear may also be the reason you continue with these relationally destructive behaviors. Some times it stems from the fear that we are inadequate in some way, and the other interests reinforce us and build out esteem a bit. Unfortunately, it is usually a bandaid fix for a gunshot wound, so to speak. This is because the root of the problem is not being addressed, only superficially through other people. The positive feelings won't last because they are external rather than building from the inside out. So, the need to continue these behaviors cycles on.
I would hope that since you have a wonderful partner now, your motivations to get healthy may help you do a little therapy and work to build positive feelings of adequacy and esteem from the inside out, rather than continuing the external, superficial fix.
I hope this makes sense! Please let me know if you have further questions. Gina