This is amazing news to hear. All you need to do to return to the church is return! Show up at mass!
Now before recieving communion you’ll need to go to confession because it is the very body and blood of Christ and you would not to take him into your temple, if sin is in the place where he should be.
As far as the teachings of Christ are concerned, he didn’t talk about divorce being adultry, but divorce and remarriage is. What will probably need to be done is the first marriage needs to be looked at to see if it was actually a marriage. There are certain criteria that needs to be met at the time of going in on the marriage for it to be a marriage. If one of those were missing, like free consent of the will or something like that, then no sacramental marriage took place. If that is the case then you are free to marry someone else (most likely your current legal wife.)
All marriages are assumed valid until proven otherwise. So right now it is assumed you are married to the first wife (unless she died.) So by celebrating the marital act with your current legal wife, it can be considered adultry. So abstain until this process goes through so you can recieve communion.
Make an appointment and talk with a priest about these things. They should know more than most internet armchair cannonists. Most importantly pray. Pray without ceasing, and he will guide you. It is so great to hear the good news, we here are so happy for you.
