Thanks for your question, I'm happy to help you today. First of all, it's not so strange that you're having trouble getting over someone you were with for 15 years - after all, that's a long time to be in a relationship, and you both have obviously been through a lot of ups and downs together. What makes matters worse is that you found out she was cheating on you, which is never easy to hear, but even harder when you're with the person, who you thought you could trust, for so long. And unfortunately, it seems that she tried to manipulate not only you but the people you turned to for help. So you're really dealing with a huge betrayal on many levels here. The first step is to not blame yourself - you didn't do anything wrong, you were misled and maltreated by someone you thought you could trust. This sounds easier than it is, because your natural instinct is to doubt yourself and think that you did
something wrong, when instead, you were taken advantage of. She - and not you - is wrong. So don't blame yourself, and avoid talking down to yourself. Try to catch yourself whenever this happens so you can actively, consciously stop the negative thought patterns. Secondly, even though you say you went to counselors and psychiatrists together, it might be worth it to think about seeing someone on your own - individual counseling can give you a place to discuss your feelings about the relationship and work through your feelings of hurt and betrayal. You don't need medication for this to take place - you just need to establish a relationship with a professional you can truly trust. Third - give yourself time. It's natural to feel the way you're feeling and anyone else in your shoes would be feeling the same way. It takes time to get over a betrayal, and your heart needs time to heal. You need to be patient and try not to rush things, because healing occurs at a different pace for everyone. Focus on yourself for the next few weeks/months - spend meaningful time with your kids, friends and other loved ones. Surround yourself with people who care about you and who make you feel safe - this can help you rebuild your self-confidence and trust in others. And when the time comes - and you'll know when it's right - you'll be ready to open your heart again to someone new - but don't push this part, it will happen when you're ready.
I wish you luck. Please let me know if you have any further questions. Best wishes.