I was the "new one" too... Yes....he did get sober but he did not continue working a recovery program. When he quit "recovery" he reverted to "addict behaviors" only he wasn't using. The drugs he used instead were entitlement and anger. Now I've closed the door on our relationship and I'm sure that his 1st ex wife is crowing about that.
The "new one" isn't getting a new and improved version of anyone but it's really easy to believe that they are. Time will tell.
Continuing to receive texts/emails is only going to keep hurting. I found it impossible not to read things when I receive them so all I know to do is stop them before I have the chance to see them....so blocking and placing things in spam really worked for me. Do I still hurt....yep....I do....but the raw and jagged feelings don't surface when I don't have contact with him. I tortured myself with contact and finally I realized that it had to stop.
It takes what it takes though....everyone gave me the same advice to go no contact and it took me awhile to get that it wa imperative to do that. Hopefully, you will realize that taking care of you is woth it and will do the stuff that helps you to get away from the painful reminders.