I can relate to what you said...I told my H the same thing. Well my words were...."it scares the hell out of me that I now understand why some people have affairs that still love their spouse." I also told him in a C session that same thing and that I did have a boundary, but that boundary line was constantly moving. Now...in hindsight...that was womanese, he was probably going ?????? I, like you and Honeypot, also craved attention, validation etc....but the fact is you want those things from your H if you want to stay M. If you want to find it from some other man...get out.
I'm going to agree with Honeypot though. You've told H how you feel, you told H you feel you are on the verge of an A, you've told him you don't think you can remain in the M the way it is. So now, if he doesn't take action.....move out, or move him out...whichever, but don't allow his inaction to justify an affair. Cally if you have been doing this for 8 years use the M as your boundary, if he doesn't do anything then show him you are serious by separating, not by cheating. Cheating will only do damage, it's not a boundary....and if you cheat, you cannot put it off on him, it's YOUR choice.