Need advice: I cheated on my boyfriend.. But we stayed together

I emotionally cheated on my boyfriend last April with a coworker for a couple of weeks. I hated my week on week off job hours away from where we lived and I don't remember what compelled me to get involved with my coworker. I decided to break things off after he tried to get physical and told my boyfriend about everything that transpired including that if wanted to break up, I am ready to accept it. I ended up getting a new job where I could be home every night and never spoke to the coworker again.

But we didn't break up. We stayed together and for the past year I have been swallowed by guilt, shame and regret. There are months where everything is fine and everything is as good as can be, but every couple of weeks when we'd try to communicate on our feelings again, it would devolve into crying, sobbing and me apologizing. My boyfriend and I have agreed to do couples counseling which will start later this month.

For those who have been cheated on/cheated in the past with their partners and came out on the other side still together, what was the experience like? Is it worth it to mend a relationship just because you love them? Is it a lost cause? Any advice appreciated.