Hi Op
I am relieved to hear you have pulled back from the brink, and are starting to ask questions about what you can do.
Can I suggest that for now, until you have all the bits of the puzzle eg diagnosis, treatment etc, you re frain from making any big life changing decisions right away.
Start with this, who knows what? what does DH know or suspect, you said you asked for a seperation or a divorce is that right? if so what was his reaction?
Do you feel able while the kids are at school, to sit down with a cuppa, and write down how you felt in your marriage, you mentioned the other man and loving him for 28yrs, can you give any more details about this. If you can seperate the issues as they stand, then there is less chance of lumping them all together and seeing them as this crisis that cant be sorted out.
if you look at this logically (sp) if you had not caught an sti then you and the OM might have been making plans to be together, and dh would have known anyway, because I presume this might have been the end plan?
Now it might be the the OM might have got cold feet, and this sti thing is a red herring and has given him an excuse to walk away. That is his issue and you have no control over that, he might have down this anyway, either way he might have left. Sometimes the fanatasy of something is better than the reality and this is what might have happened for him.
It sounds like as well, and correct me if I am wrong, that you are more devastated over his loss, than maybe the sti, because the sti and the consequences for dh have been pushed to the front and have to be dealt with more quickly than maybe you wanted? this is not a judgement but me thinking out loud, to see where things actually might be in you world right now.
The last thing I will say is this, this is your life and only you know what you want, I am only interested in you and your kids, and your continued staying around for them. Affairs and sti's are of no consequence because there are bigger things at stake. Make your decisions based on you and not your DH, this is a selfish act yes, but you DH and the OM are grown ups your kids are not, and they come first no matter what.
People make unwise choices op, I dont think for one minute that you would have done or gone through with any of this , if you had any idea this would be the result. but it has happened and you will deal with it, because the other choice is far far worse.
x