TMS equivalent?

I still have a LOT to learn, and I'll do my google research on this, but I wanted to hear from you all...

I don't know much about this TMS equivalent business, but I've seen many of you refer to depression in regards to it. I've had issues with depression since I was about 13 or 14, moderate and relatively short bouts, generally speaking.

I'm curious about something a little less obvious, but concerning to me. It's like my feelings are flat, or very muted. When this happens I also lack motivation, my energy level is low, though I'm not exactly tired. I'm not happy, but not necessarily unhappy either.

It bothers me because it really affects the way I interact with my family.
Can you guys shed some light on this, provide links, etc?

 

[Deleted at BeWell's request]