I have just caught up with the posts since I was here last and I do so agree with (was it jmg?) who related the story of the refugee. I kept thinking much the same myself.
When I was struggling to look after my girls after their father dumped me, people used to say how strong I was and how well I was doing, but the fact is, if you don't have a choice, you just get on with it, don't you? But at the end of the day, that is what managing is.
Another point I wanted to make is that I believe the secret of happiness does not lie in finding the perfect partner, or soul-mate, or never being cheated on or lied to. The real happiness and contentment comes from within yourself.
I too love my husband to distraction (your words, in your very first post after you found out). I consider him my soul-mate and best friend, and I too would be utterly devastated if he did this to me.
But I feel strongly that I would survive, and find my happiness again. Because you can't count on other people to be your life or your happiness. You can't expect they will always be there for you. They die, they change, they betray you and let you down. And none of us knows if the husband we adore may one day do one of these things. All we can do is weigh up the likelihood and try to pick someone with a good track record who seems unlikely to let us down. (As for those who die, no one can be protected from that.)
You have to be self-reliant so that you have a good base to fall back on if other people let you down. If you can look in the mirror and like the person you see, you have a good start. If you have nothing to feel guilty about and have treated other people properly, if you have kept your promises and fulfilled your responsibilities, you are doing well. If you live by well-thought out morals and principles, that's brilliant. If you have fashioned your life so that you can get the best out of it, and incorporate elements that exploit your talents and interests, that's even better.
None of these principles involve other people. They are about you and your own inner life - and that is where happiness is rooted.
I am not for one moment saying that I would not be deeply miserable and disappointed if my dh let me down. I know I would be devastated. But I would tap into my own essence and use it to build myself up again. I would know that light was there at the end of the tunnel and I would go on hiking until I reached it.
I am lucky that I think my dh has helped build me to feeling like this. He is one in a million and picked me up from crippling depression, building me and loving me until he brought me to this.
All the same, much as I love him with all my heart, my life belongs to me, not him, and without him I would still have a happy and fulfilling life, after a time spent in recovering.
So can you. Focus on YOU. Make a plan for your life, and GO FOR IT!