Your website is wonderful and I am learning a lot! I have seen similar questions but not quite the same.
I’m not sure if I was a believer at the time of my marriage or afterward. I grew up in the church and knew who God was but I did not have the Holy Spirit until earlier this year. I may have accepted Christ into my heart but I am unsure. I didn’t live a life pleasing to him until recently.
My unbelieving ex-wife was going out with her coworker. I found out they had gone on dates. She said she needed space and time to think. A few months later, she says that she wants to be alone and that she isn’t happy. I try to make things work and offered to forgive her in time. She says she’s leaving. I tried to file for divorce immediately, but I can’t because it’s too expensive in the state she lives in. I had to wait until I was back in my state of residence. I find out she went on vacation with the coworker the weekend after she left me, so they obviously had an affair. I am devastated and heartbroken. A few months afterward, I went to bars and sleep with women to feel better. Soon thereafter I finally filed for divorce because of my ex-wife’s abandonment and infidelity. I had sex prior to me having filed for the divorce (maybe 1 or 2 months prior). I totally had forgotten about it.
Earlier this year I rededicated my life to Christ. Again, I’m not sure if I had dedicated it before. The Holy Spirit lives in me. I found a wonderful Christian woman and things are getting serious. However, we need to know if I am okay to remarry.
I don't know what church you have been a part of, but it is clear that it isn't one that follows the teachings of Christ. You use phrases that are common in various denominations but are not found in the Bible. Therefore, the first order of business is to make sure you know that you following God and doing as He commands. "By this we know that we have come to know Him, if we keep His commandments. The one who says, "I have come to know Him," and does not keep His commandments, is a liar, and the truth is not in him; but whoever keeps His word, in him the love of God has truly been perfected. By this we know that we are in Him: the one who says he abides in Him ought himself to walk in the same manner as He walked" (I John 2:3-6). I would like you to read How to Become a Christian, read the verses cited, and see if that matches what you have done. If not, then make corrections.
Your wife left you for another man. She is guilty of adultery. Technically, the divorce is because of her adultery. The fact that you claim to be a believer and she doesn't believe has no bearing on your question. All the world is under the Law of Christ, which is why most of the world is in sin. There can't be sins if there is no law (Romans 5:13).
It doesn't matter that your wife abandoned you and was having sex with another man. It doesn't excuse your drinking and adultery. You chose to do this, even though you knew it was wrong. However, it seems you have turned your back on your sins.
Since you claim that the divorce was not due to your adultery or your desire to marry another woman, it appears that you can marry again. The sincerity of this is something you'll have to deal with when you face God in Judgment. It isn't something I can judge from the sidelines.