I need a little clarification regarding your marriage situation.
- Which husband died?
- The first or the second?
I'm not a canon lawyer or a priest, but here is my take.
- If it's the first, you're free to remarry, so I don't believe an annulment would be needed to bless the current marriage in the Church even though he was alive at the time you remarried.
If your second husband died, then you're no longer living in the technical state of adultery.
In either case you are correct, you need to go to Confession and certainly need to discuss this with a priest. As for your fears, let me simply say, that any priest worth his onions, will greet you with a warm welcome and help you through whatever is necessary to make things right.
If your second husband is living, and your prior husband is dead, you'll need to go to Confession and get your second marriage blessed in the Church. That's providing that your second husband doesn't have a prior wife, in which case, he would need an annulment or at least have his first marriage looked at but, as I said, you need to discuss all this with a priest.
I understand your fears but once you actually start your Confession, the fear will leave. Place your faith in Christ who loves you unconditionally.
I have many friends that are priests and they all say, one of the most rewarding things for them is to hear the Confession of someone returning to the Church.
It will thrill him, that God has chosen him to be His instrument of reconciliation. A priest is like a doctor. He is there to cure and treat spiritual illness. Just as doctor is always thrilled to help a patient get well, so to a priest will have the same reaction.
I went 20 years without going to Confession. I feared it too and I was drug addict and drug dealer who committed every crime in the book, short of murder but the moment I started my Confession, the weight just lifted off my shoulders and the fear disappeared.
So what it's going to take on your part is a leap of faith. That's a leap that can only happen by grace so look to Jesus, the Author and Perfecter of our faith. Get your eyes off yourself and put them on Him.
We will be praying for you.
Under His Mercy,