Julie, this is a very complex subject and I completely agree that you should talk to a priest.
My wife and I, both in our second marriage, after divorces, just joined the church. Her first husband is deceased, so there’s no problem there. My ex-wife is still living and I’m working on an annulment.
Re the previous comment concerning the cost of annulments, please don’t be put off. I’ve been told when the processing of my annulment is complete the diocese will tell me what they spend on it. After that I can pay all, some, or none of it. I understand this might be different by location, but please don’t hold the church in contempt before you investigate it.
About remarriage and communion, as this new Catholic understands it, the answer may be no, you can’t. My wife and I can, because we are living as “brother and sister”, that is, not having sexual relations before the annulment is granted.
Remember, all of this is complex. You need to be patient and just walk through it. Remember too, you are as worthy as anyone else to become a Catholic, and the day you do, you will be as worthy as any other Catholic.
God bless you and your family. Don’t hesitate, make an appointment with a priest right now!