I don't have near the experience as some of the DB'ers on here. I compared my well being, and that of my children in a then and now sense. In the end, this is what i have learned... Appreciate what you have. You sound like you are doing well on your own, but trust your instincts. Ill never doubt mine again.
In my case, my current situation was better, i've dated some which was hard since i have my daughter 99% of the time. I hit a moment like yours just recently where i caught myself wondering, what if.... Then she reminded me how much she liked to yell and carry on.
There is my advice, trust yourself and your decisions. Everyone here could say do this or do that but unless its what you actually want you wont listen.
anyway i have a tendency to carry on so ill zip it at that. If you love her, go for it. If you love her but are done with the crap, maybe a little more tentative "dating", if You love her but have no more fight for the marriage then, there you are.
the key thing is, you love her. Just dont base everything on that.
ok SHH MLB
Being deeply loved by someone gives you strength, while loving someone deeply gives you courage.