It sounds like depression, and depression doesn't always have an outside cause. It could even be hormonal. Have you been to a doctor?

Even if it is empathic, there are defenses that we all use that normally filter out unwelcome emotions from people who ... for lack of a better way to put it... don't matter.  When you're too open, everyone else's crap becomes your crap, and that's not what you want. You could be going through a spiritual awakening, and as such, how you deal with it determines how long it takes to get through it and emerge whole and reborn on the other side.

I have been going through something similar. Here's what I do. First, I work on all my chakras. Second, I went to a doctor. He diagnosed me with depression and gave me some medicine. I know that's not the supposed witchy thing to do, but I can say that I have had no ill effects, and it's only temporary...most people make the mistake of thinking the medicine will fix everything...no, you have to work in other ways to improve your emotional state.

Third... get some sleep. Sleep more than you are "suppose to"... go to bed a few hours earlier than everyone else. Give chores to other people in your household to make up for it. Explain that you are in the process of healing yourself and that you need extra rest for a while. It won't be forever.

Get outdoors. Nothing replenishes your energy better than being with nature and being exposed to natural light... the light of the moon and/or the sun.

Stuff like this happens from time to time. It's not your fault, and it very well may be an onslaught from other people's energies. Who knows? But what's important is that you pick yourself up and you get yourself through it.

If you need someone to talk to, drop me a line. It helps to have an understanding ear.