ok guys I need help.....

Sounds like you have basically answered your own questions. Listen to what you are saying:

there is a new girl at his work that is pretty, funny, and smart, ( all I thought I was )

Why do you think you are no longer pretty, funny and smart? You are obviously feel undesirable in this relationship. I have no doubt you are all those things - but this relationship is making you feel "less than".

I am worried that he will cheat on me with her here is why ( and this is what I told him): 1.When we fight he says that ther is nothing between us anymore.

Well that's pretty blunt. The smoke signals are right in front of you. Your relationship is obviously in distress - so what are the two of you doing about it? Are you sitting down and talking about what is holding back your relationship and coming up with ways to fix it? Are you seeking any sort of couples counseling? Or are you just hoping things will magically be fixed? They won't. You have to work at it.

2. his last girlfriend ( of 5years ) that he loved very much( even though she lived far away) he cheated on 3 or 4 times.

You know the potential is there and you don't trust. Major issue - and one not easily overcome. What are the two of you doing to build your relationship and give a strong foundation of love, support and trust?

3. a girl being married does not bother him , I was when we got together( grantid I was in the last stages of my divorce). His response was that he loves me but I cant help to still think, espically since things are not as "Hot" latley as they have been.
well guys I need to hear the HONEST truth on what you think about this..... [/b]

Again, an acknowledgement that you know the relationship is in trouble. Sounds like the two of you need to sit down and really figure out what you want out of the relationship and if you are heading in the same direction. You may end up finding out that deep down, neither one of you is getting what you need out of it... could also be that you come to the realization that you really want to work it out no matter what it takes. In either case, the only way you are going to find out is to discuss it very calmly and in a non-threatening manner (i.e. not in the middle of a fight or heated debate). If you do wish you continue the relationship, I would really suggest you guys look into counseling. It really sounds like that is something that your relationship greatly needs if you want to make this work.

Best of luck!
SpongeBob