Hello Drummergirl,
I can completely relate to the insecurity you're feeling right now - seperation from a long-term partner is a very unsettling situation as it pulls the rug under your feet temporarily even if you're the one who decided to pull that rug... it triggers all sorts of complex emotions, fears (e.g. abandonment comes to mind even if you're the one doubting the relationship) and guilt at the same time; I personally find that to be one of the most challenging situations one can face.
Still it's been an ongoing issue for you for a very long time and I think you really haven't been taking that step light-heartedly but have come from a very reflected and in fact sober point of view. So I would say: Trust yourself, trust that by seeking that discussion with your boyfriend you've done the right thing as the situation wasn't sustainable or emotionally fulfilling anymore for both of you. This doesn't necessarily have to be the end of the relationship; I think you just voiced/ shared your feelings and doubts with the person they belong to; it will create a new dynamic. That is honest even if it seems hard at the moment but if your relationship is to survive and thrive it'll be on changed and certainly more mature terms.
You're much too smart to drink/use in a situation like this, so let me just say I think of/ feel for you and wish you well from the bottom of my heart. Be that strong person that you are and that you document here on a regular basis.
I need to go to bed now, it's really late here already. I'll check in tomorrow again. Be well.
Julia
PS: I'm not a native speaker so apologies for potential mistakes...