I have been with my husband for 10 years (my entire 20's). I recently, 6 months ago, was told of him supposedly having an affair with this female. Also 6 weeks prior to this he told me he wanted a divorce, which was also the day before my 30th birthday. So I checked phone records and sure enough they talked and texted all day for about year. I confronted him and he denied the affair. We worked everything out, I thought, because we are still married. I asked him to stop talking or texting her but he continues to talk to her occasionally behind my back and has gone so far as to store her number in his work phone under a false name. I could not check records on his work phone obviously. I tried not going through his phone because that made him mad but when I do I discover something new. He promises they are only friends but I told him the last time I wanted a divorce if he spoke with her again and he did. He continues to lie about contact with her but swears it is innocent friendship when I confront him. He says they are just really good friends.
Please help with some advice!

When you say you "worked everything out" after you confronted him about texting a talking to another woman for a year, what does that mean.

Did he say that he would end the affair? Did he?

What changed, is what I'm asking, from the point where he asked you for a divorce, you confronted him about this other woman, and "worked everything out".

What were the problems leading up to the near divorce. Are there children involved?

It doesn't sound like the two of you have worked anything out. Why you both decided to stay together I have no idea. He's at the very least emotionally cheating with someone, and betraying your trust by contacting her, and you don't trust him at all. There is no marriage here.

If the two of you hope to salvage this I would suggest marriage counseling.

He is emotionally cheating with this woman at the least. He has betrayed your trust. There is no marriage without trust.

Yes I agree with Alty and Homegirl he has betrayed you and he is emotionally cheating. I just think its plain disrespectful to your marriage for him to still be in contact with her.

The only thing that was worked out is now he knows he got to try to fool you by being sneakier.
Work on a plan to get out because he is not going to change.

When you say you "worked everything out" after you confronted him about texting a talking to another woman for a year, what does that mean.

Did he say that he would end the affair? Did he?

What changed, is what I'm asking, from the point where he asked you for a divorce, you confronted him about this other woman, and "worked everything out".

What were the problems leading up to the near divorce. Are there children involved?
There are no children involved. He said he wanted a divorce because he was not happy. I work a lot I am the main income of household. He loves hanging out and drinking, while I do not because I am very tired. As far as
Working it out he said he was going to stop talking to her but it has been six months and I have caught him 2 or 3 times but it was not nearly as much texting or calls.There was no physical affair but definitely emotional. I know they talked about me. I have contacted her several times too. But same story "we are just best friends". I do not want to leave him over having a best friend but I do not want it hid from me. I also know this girl vaguely but would never say we were friends before I found out,mainly acquaintances. When it is good it is awesome but when it is bad it really bad. I feel lost. I just got off phone with him and he said he had not spoke with her and will not, but I have heard that how many times. I feel weak and stupid, which pisses me off because I am a strong, jndependent woman. I thought :(

It doesn't sound like the two of you have worked anything out. Why you both decided to stay together I have no idea. He's at the very least emotionally cheating with someone, and betraying your trust by contacting her, and you don't trust him at all. There is no marriage here.

If the two of you hope to salvage this I would suggest marriage counseling. he refuses counseling but I just posted an answer to a question that will give you more details on situation.

He is merely hiding it better now.

You said, if he did not stop, you would divorce him, so divorce him.

Who cares if they shared the same crib as babies, they were having an affair, so time for them not to contact any longer

I think your marriage has deeper problems. If you are the main breadwinner and are too tired to goof off, he may feel both inadequate and resentful. I don't know if you work too much and don't take enough time for fun, or if he is too irresponsible about adulthood and the future.
Rather than dwell on something you can't prove, how about sitting down with him and writing down each aspect of your relationship that doesn't gibe, and see if it's solvable? Work hours, money differences, time spent on fun - make a list. Hash it out.

If not, end it now, and be glad there's no children to complicate things.