Trust takes time and that's okay. Restoration/reconciliation is a process that is going to take a lot of hard work and commitment. Although people like to think that faith is simply believing (although to some extent that is true), real faith is when you actually take action - even if its just baby steps.
The passion, the fantasy, all the beginning fun stuff you mention can come back to your marriage if both parties are willing to make it happen. That is something that has to be constantly worked on and maintain. It is real easy to get into some routine where we stop doing the things we did in the beginning. Complacency is such an enemy to a good marriage/relationship.
I would consider writing down and at least pondering the type of relationship you want. What types of communication, intimacy, playfulness, thoughtfulness, etc do you want to experience with your ex? Really try to get specific. Those experiences are the types that you ex needs to be trying to achieve for you and a lot of times those needs need to be communicated in a sincere and safe way as us men don't always get it or realize what our spouses want. You will also need to know what your ex expects/wants out of the relationship. Regardless, it is going to take energy and work to make it happen - but you can do this.
Do be careful with the new guy. If you want to try to make things work with your ex, I'm not sure having the new guy around is going to help your cause. I can understand your predicament though and I know that these things are not always easy. I'm not saying to ditch the new guy, but just to be careful. For things to really work out with your ex, your entire heart has to be in it. That can take time and that's okay. The key here is to be committed and to not give up. To do everything you can to make whatever relationship the most it can be.
