The prohibitions are in Canons 915 and 916:
Can. 915 Those who have been excommunicated or interdicted after the imposition or declaration of the penalty and others obstinately persevering in manifest grave sin are not to be admitted to holy communion.
Can. 916 A person who is conscious of grave sin is not to celebrate Mass or receive the body of the Lord without previous sacramental confession unless there is a grave reason and there is no opportunity to confess; in this case the person is to remember the obligation to make an act of perfect contrition which includes the resolution of confessing as soon as possible.
Honor to you for your restraint. I don't know whether or not you actually attend Mass, but if you don't, if it's not too much, I encourage you to go. Pope Emeritus Benedict made clear that even those who must, for these circumstances, abstain from the Eucharist are nonetheless to otherwise fully participate in the life of the Church, including, and especially, attendance at Mass.
Have you privately discussed your situation with a good, solid priest? There is the possibility that your first marriage wasn't sacramentally-valid.
It might be worth the inquiry.
My best hopes and prayers for you.
sitetest