My relationships are deteriorating. How can I stop this?

Lately, I’ve been noticing that people aren’t responding to me as they were before. I’ve also noticed that I haven’t been able to be the same either. I’m in a blue funk. I can barely concentrate, because of constant negative emotions and thoughts assailing my entire being. I know people wouldn’t give a damn if I were to tell them I was depressed. I can’t even think straight enough to have a decent conversation with anyone anymore. (or maybe I’m able to think, just not able to converse…)

How do you maintain your relationships when you’ve fallen into a rut? Is this just a stage of my life where I’m changing? Have I changed into something so incompatible with people? Will I become completely alone?

I’m going quite crazy, but I do not want to go to a medicenter