You are not a weak person at all... I can only speak for myself, but I know I definitely struggle with the same fear of losing my H altogether. But 1) they are already gone. If my H signs the final D paper tomorrow, my life will not change in any way from how I have lived the last year and a half. It's just a piece of paper and he's already gone. And 2) fear holds you back from doing the very thing MOST LIKELY to bring him home--moving on and bettering yourself. Trust me, MB...I have done it all...fought, guilted, tried to convince him and *nice him* back home...it doesn't work. There is nothing you can do to bring him home, so you don't have to worry that *not* doing something is going to make any difference. It isn't. This isn't about you. It's about him. The only thing you can do is for yourself to make sure you are the most attractive option when he finally spins out and crashes. That's when you will have a chance to save your M.
All trying to be Mrs. Fix-it does is make us look less attractive to our spouses because that sort of behavior reeks of desperation and lack of self respect. Let him go. You are TOO GOOD to be treated the way you are being treated. Think about all the great guys out there who would think you were nothing short of amazing if you treated them as you try to treat your H. He does not deserve you right now.
I'm not saying it's easy... It hurts like h-e- double hockey sticks. I will admit to way too much navel gazing behavior, analyzing and second guessing H's every move, way more often than I should (you can read about it in full detail on my thread...lol). But I'll be darned if he'll know about it. Sometimes I practically have to sit on my hands not to send that text or email and temp check or just see what I can get from him. But I do it because I already know...I have already done everything else and it was not the answer. Anyway...do you really even LIKE the person your H is right now? I know I don't. I miss the man I married, but my H is no longer that man, and never will be again. He might be someone even better someday, just like I hope to be someone better too...but right now, he isn't. And I don't want the jerk who is currently invading his body. I'm fabulous and he doesn't appreciate me enough. You are fabulous too (and so is every other LBS here). Don't ever let him make you feel otherwise.
I will admit to way too much navel gazing behavior, analyzing and second guessing H's every move, way more often than I should (you can read about it in full detail on my thread...lol). But I'll be darned if he'll know about it. Sometimes I practically have to sit on my hands not to send that text or email and temp check or just see what I can get from him. But I do it because I already know...I have already done everything else and it was not the answer. Anyway...do you really even LIKE the person your H is right now? I know I don't. I miss the man I married, but my H is no longer that man, and never will be again. He might be someone even better someday, just like I hope to be someone better too...but right now, he isn't. And I don't want the jerk who is currently invading his body. I'm fabulous and he doesn't appreciate me enough. 
You are fabulous too (and so is every other LBS here). Don't ever let him make you feel otherwise.