Losing the motivation
Very good thread, as we all deal with getting older and going through changes and making changes.
We men, when there's a problem, it's our nature to want to take action and fix it. So, first thing, go get a physical and make sure nothing is out of whack.
Get away for a few days, not to old haunts that make you feel empty, but maybe a place you always wanted to see. Visit an old friend, take your time, stop at places that catch your interest along the way. Chat with people you come across. Just spend some time seeing sights, being around nature, and not worrying about anything.
OK, I know this might not be your thing, but, if you believe in a greater power than yourself, ask for a way to help others to present itself. Giving your time and effort to help people who need it will get you out of your rut and give you new energy. Helping people is the best medicine for your body and soul, and you will get new, good people in your life too. Good luck!