I think you feel like you should be grateful that he came back and says he loves you, and that it sort of 'cancels out' the fact that he left in the first place. But even if you are glad he's back, you are still left with an uneasy feeling that it could happen again because maybe you aren't exactly sure why it happened in the first place.
So like the others, it's him that needs to be earning your trust back. He left, not you. He met two other women. Yes, you're glad he's back (right?), but feeling secure again can't be rushed. You need time. It sounds like he's being nice, etc., but if there's anything else you need from him, you need to let him know.
If you're not ok with the friendship, ask him to stop texting her. There's no need for this, not in your situation. If I asked my husband to not be friends with a woman, I would expect that he would respect my wishes. And vice versa.
He hurt you, and it's great that he's making it right, but only you know when that will be and how you'll get there.