You aren’t scared enough! You know this is getting worse. You know you haven’t been able to stop it on your own. It’s well past time for you to get some help. Even the “voice” knows it.
Since this is a recent change in your thinking, I’m particularly interested in pursuing a medical explanation. If you haven’t had a medical check up in awhile, see your primary care physician ASAP. There are medical conditions that can cause irrational thinking. Sometimes it is as simple as a vitamin deficiency! Really.
But if you are medically fine, you do need to see a mental health professional for an evaluation. Please don’t hesitate to do so. A therapist may be able to identify what has changed and will offer you options for addressing it. You aren’t obligated to do anything other than listen. Chances are, though, that you will learn some new ways to address your feelings of being unlovable and a “loser”.
At 50+, you deserve to have more going on in your life. A therapist will give you the support you need while you figure out how to make it happen.
I wish you well.