I’m in my mid 40s. I’ve lost all confidence in my ability to find a partner. Is that usual for my age?

You are trying to project the responsibility to circumstances. Recognize that this idea is disempowering you. Learn to be happy from within yourself. Take responsibility for this, learn from others when necessary but never subscribe to the idea that something other than your own being is the source of your fulfillment. You need to sincerely look at yourself to know who you truly are. Be persistent in your sincerety. You have always created your experience of life whether you have been conscious of this or not. So awaken! I assure you, partners will be a non-issue for you whether you have them or not if you sufficiently have awakened to who you truly are.