kiwibella, I'm so sorry that you're going through this. You've had some really insightful posts from several posters, particularly FizzyGreenWater; I'd definitely want her to be my counsellor if and when I needed one.
You're also getting some really crass posts from posters who, with assumed best intentions, are really putting the boot in by suggesting that by staying, you're setting a poor example to your children, not having self-respect, etc. crunchiebabe, I'm glad that you feel vindicated in your choice but your post must be a real punch in the guts to people who follow the other path, you know, the one the OP said she had chosen.
OP, I didn't stay in my relationship when I discovered the cheating but, I could have, because I wasn't actually that invested, because it didn't floor me for that very reason. How I would have been had I been in pieces, I don't know, I can't say. That's the point really, whilst everybody can wax lyrical about what they would have done/have done, it's not from your perspective. People are not identi-kits, the relationships we have with them are not the same, the feelings we have for them and in our relationships are not the same so it's really quite pointless to overlay our own experiences on somebody else.
You have the right to choose how you handle this and you should have the right to post without being judged for how you do it. Sadly, that's not the case in reality.
If you stay and it works out for you then that's great. If you stay and then change your mind, that's great too. Whatever you decide is the right thing for you. Best wishes to you.