Sorry you are struggling. First of all let me just say that whatever you decide will be the right one for you. Don't let others make that choice for you. For some of us and A is truly a dealbreaker.
For some of us we were kind enough to offer the gift of R, to only be TT'd to a breaking point, or loosing our own self respect because our spouse doesn't do the real work of R, and continues to abuse us by taking it underground or not fixing the broken things within their own selves to heal and repair the marriage.
Few of us are lucky enough to be able to offer the gift of R, and in turn have a spouse that is willing to do the work needed to heal and have a healthy relationship. Many of us who do attempt R stumble a bit initially.
You don't have to make a decision today tomorrow, next week or next month. I understand what you are asking about how do you trust, and how do you love, and how do you repect again. All I can say is this:
When your spouse does the work to heal himself, and really truly gets the damage they have caused, and through time, and them proving themselves over and over you slowly begin to gain trust, and the love that never really went away becomes stronger, and you heal yourself. You become stronger, and your partner becomes stronger, and you realize this person is not the same one who had an A, and chose to break their vows, your heart, and the M. This person is doing anything and everything they can to heal the M, mend your heart, and has complete understanding of your damaged trust.
It takes hard work, and lots of it, over months and months and years to get there, but I can honestly say at 5+ years it is well worth the work.
I can also say if I didn't have a spouse that did the work, and didn't put forth the effort, or understood I would not still be married. I also know that I would be fine on my own.