Good on you, hold tight. And thanks for coming back. I really genuinely think it shows great courage on your part. I am so glad you know the truth about some of those things now. I humbly suggest you revisit those old threads now, in the knowledge that she WAS at that party and that deleted phone call WAS her and try and think about yourself as you would a good friend. it is so awful to see someone you care about treated that way. Right now you will be 'high' somewhat on the honesty of his confession. This tends to produce a sort of 'hysterical bonding' along with a sense, finally, of being in control. And that adrenaline can be useful. Sometimes it can make people hopeful about a future that they think has 'finally' become honest and positive.
However. Just be aware that these 'confessions' have come about through your discovery. Not any great character change on his part. He has simply, over and over again, deceived you and done whatever it is he wants. Until such a point that he has found out. I would also point out, without wishing to be doomy, that that which we discover about infidelity is, most of the time, the tip of the iceberg. The vast majority of infidelity goes undetected in life, so when we find stuff out, it is a safe assumption (not always true, but safe) that there is more, sometimes much more, than we know.
I am very glad you are getting him out of the house. Please know you can come for support here. Sometimes, when we are in pain, we so desperately need support and affection that we return to the person who is responsible for causing that pain, because they are the person we are used to being loved by. it is very very important you try and find affection and support from other sources right now, so that you can be sure that whatever you do next if based in a reality of what you want, rather than a need for someone close who loves you.
Please follow through on this, hold. Please. No matter what he says. If not, I really believe you will regret it forever.
With respect
Blood