It is wonderful that the Holy Spirit has led you to seek full communion with the Catholic Church. Congratulations! and a warm welcome!!
As I understand it, any marriage between two Christians may be presumed valid. The ministers of the Sacrament of Marriage are the bride and groom, the priest or deacon serve as witnesses so there is an initial presumption that any legal marriage between Christians is valid, especially if witnessed by a Christian minister. Catholics are required to marry in the Church however, except for extreme circumstances. For example, you are living in a country where Christianity is banned and there are no priests available.
Again that's my limited understanding. I also believe that granting an annulment in such cases, while it might be little time consuming, is very easily granted, as it indicates a lack of understanding of the Christian Covenant of Matrimony, prior to entering into it. Also, the process has been expedited. This should not be an issue with you entering the Church in the meantime but if you want to remarry it will likely need to be addressed. It sounds like you want that option so you should look into it. It's possible you don't need an annulment but it will have to at least be looked at.
As Mike said, the first step is contacting a local priest. He will help you set the wheels in motion for both:
- your entry into the Church and
- for an annulment if the latter is indeed necessary.
In the meantime, I want to encourage you, to attend Mass as often as possible. While you can't receive the Eucharist, you can go up and receive a blessing when others receive Communion. Just ask preferably (the priest or deacon) or even the Extraordinary Minister to bless you.
You can also make what we call an act of Spiritual Communion. That simply means praying that Lord come into your heart and commune with you. (if that sounds familiar, it is essentially what Evangelicals do when they ask Jesus to be Lord and Savior of their lives.)
If you have the time, you should try to spend some time praying in front of Eucharist, either at an Adoration Service, when the Eucharist is exposed on the altar in a monstrance (a fancy item that holds the Eucharist so all can see HIM). or you can just pray in front of the tabernacle.
If you have any difficulty understanding points of doctrine, don't hesitate to write and ask us. That's actually more our area of expertise, as opposed to Canon law and pastoral counseling. We are Catholic apologists. We provide explanations and reasons for why the Church teaches certain things. All of us come from different backgrounds. I'm a revert, meaning I left the Church, became a Protestant minister, then returned so my strength is explaining Catholic doctrine in a Protestant language. Others on the team have backgrounds in philosophy or theology. Some are cradle Catholics and some are converts. Our mission is to foster an understanding of what the Catholic Church teaches . . . really teaches . . . not the far too common misunderstandings which many hold on to.
You shall remain in our prayers. Please stay in touch. Let us know how your journey is going.
Under His Mercy,