I concur with advice given by Tush and Confused615.
To borrow the title of the book and movie, "He's not that into you."
You've been holding onto him too long, and you should have been done and gone the minute you began to suspect you were "second place," because he was no doubt in subtle ways making SURE you felt second place with eye contact with her or in other ways. Drop both of them, and you may have to cut free of that whole crowd. They're both bad people - your husband, your ex friend. Him, for seeing her after his wedding day (and probably before, when you didn't know it) and her for criticizing YOU for not letting her date your boyfriend before you married him and she slept with him? What kind of monstrous piece of work is she to write that, after having slept with the bridegroom the day after his wedding. Screw that beyotch. Oh.. right... your husband already did. So leave him now - it doesn't matter that you love him and want him, any more than it matters that an addict might love cocaine when they must stop and walk away from that bad thing.
Tell him you are soooo outta there and away from that twisted little "Cruel Intentions"/"Dangerous Liasons" kind of sick game.
Then be brave enough not to stay to wait around for his reaction hoping he will declare undying love and beg forgiveness. WALK OUT OF THERE. Also, notice your friend told you your husband "wasn't doing well" when you left. Are you sure about that? Most cheaters get all sadface to make friends feel sorry for them rather than criticize or dislike them for their bad behavior. Sympathy for the devil attempt. Not sincere. Or was your friend enjoying the drama, wanted to see you return to amp it up for pleasure of watching the fireworks? Or just saying that to make you feel better when maybe your husband was doing well - in fact, doing everyone, when you were away?
Walk. NEVER take his calls again for the rest of your life except over legal stuff required, and file tax separately if you're in U.S., because chances are he lies about everything financially, too, and you don't want the IRS to come audit you. Walk out cleanly. Liars lie.
See a lawyer about an annulment or divorce. He keeps other women on a string - your friend and his former FWB - is not remorseful and will likely continue to do this for the rest of his life unless he has a religious epiphany or something similar.
Seeing you walk out hasn't changed him a bit. He's hiding his phone, so the risk of losing you hasn't changed his player status. He just loses more respect for you and treats you more like some hanger-on girlfriend who will do for now, as he looks for someone "better," than like a cherished wife. You are already better than him or anyone he knows.
Wipe that slate clean. If you're embarrassed the marriage lasted such a short time, then either tell the truth and your family will understand. Or keep quiet for some time, move to a third city, preferably getting a job in a place you've always thought would be a great place to live, and let them know a year from now when the divorce of annulment is final and you've healed a bit.
If he doesn't care all that much about you during the most romantic and sexual intense stage of a relationship, then he's incapable of it. Notice that not only did he cheat on you, he's cheating on the friend he cheated on you with when he added the FWB to his flirtation rotation.
It's best to hurt a year than 20 years.
[This message edited by Heavy Sigh at 9:00 AM, July 23rd (Tuesday)]