So sorry to hear about your tale of woe. A lot has happened to you and in your life. I pray for you, and urge you to find your strengh and solace in Jesus.
First and foremost, if you have DB and DR, read them. If you don't get them. If you've already read them, read them again. Find yourself a support group of divorced women and attend; share; create fellowship. Plan your time with people, doing things or reading whatever stimulates your mind...just keep yor mind occupied in a productive way.
As far you XH, he may be going through a MLC, but you really need to read up on that and see if he has displayed any cues that that is the problem. Also, his working in two paramilitary organizations over 20 years certainly put a great deal of rigidity and discipline into him. Losing his job had to be a huge blow, along with leaving the FD due to unnamed problems.
Looks like your XH is having a serious self-esteem problem. He recently turned 40, job problems, he starts working out VERY hard, and he starts up with a 25-year old. Topping all of this off with his own need to be right moreso than happy, he has a pretty tough row to hoe. The 25-year old girlfriend is simply a symptom of whatever is the root cause of what ails him. Affairs are often mistakenly thought of as the problem, but they are simply a symptom of problems in the M. Additionally, your supposition that he wanted a D to simply play around was correct. He simply wants sex without the encumbrances and responsibility of marriage.
I know you want to be intimate with him, but I advise you to stop. You appear to be trying to pay to have him back by giving into his urges. Read DB and DR. Those are a fantastic starting point for recapturing who you were before this storm hit and for figuring out who you want to be going forward. YOU are the only one who gets to decide (1) what your attitude is, and (2) what you are going to do next, and (3) how fun your are to converse with because you are so well-read. No one else matters. Improve yourself. READ. BE happy. DO stuff. And certainly stop calling him unless you have a need that you MUST (not WANT) to discuss with him. ALL of this will make YOU more attractive to him.
Give him the gift of missing you. No one misses someone they feel is pestering them. One action step I did read hear was to mail articles from magazines/newspapers,internet that you think may be of interest to him, might lift his spirits, or may address a challenge he (or your son) has told you that he is having. Still, communicating, but one-way and without XH feeling pressure. I thought this was thoughtful. Perhaps worth a try.
If XH decides to date, so be it. YOU go out and do things with others, male or female, and have fun. Be certain that any men you spend time with know EXACTLY what your intentions are and where you stand. Eliminates assumptions, misunderstands, and hard feelings. Your staring at the phone and wondering what he is doing, and with whom, will lessen over time as you stay busy and enjoy yourself.
Good luck to you, my dear. Pray for God to help you to understand His will and to help you bend YOUR will to His. Pray for Him to help you understand His will and to understand that His will may not be not what you wanted or expected. Keep your mind open, keep your eyes and ears open, keep your heart open
All my best, Tom
p.s. If you are a member of a church, seek out a women's group. If you are not, seek one out. You do not NEED to be a member to take advantage of the Christian fellowship. Participate. Tell people your story. Meet friends.
p.s.s. This may be the time in your life that you only see ONE set of footprints in the sand because He has scooped up your weary body and is carrying you.
p.s.s. BTW, a marriage is a spiritual contract between you, your husband and God. Cheapening your marriage or your re-marriage to "paperwork" is WRONG and will not make you feel better about what has happened.
Letting Go Tom; JUST DO IT! previously hopeful_husband
my A: Fall 05 W found out: Feb 06; separated immediately W pursued D, final 7/11/07