Emptiness

I can't remember the last time I was happy.
I'm not sad, I don't feel upset about anything but I'm just not happy.
The main emotion I feel is agitation.
I get snappy at my partner and I feel horrible, he's sick of it..
My best friend tells me this is how she felt for so long, until she finally went to the doctor and broke down and was put on medication.
I'm the kind of person who doesn't like to take meds, I try not to take pain relief unless I really need to. So the thought of antidepressants isnt appealing to me.
But I don't know how long I can go on feeling like this.
Can anyone share their experiences going through something similar?