Why cant i cry anymore?

okay, well pretty much for the last few years ive been depressed, on & off, for abt 2 years i could NEVER cry, no matter what happened. i felt like i was bottling everything up, my eyes would sting, my lip would quiver, i would curl up in a ball & no tears? it really frustrated me. then a few months ago (& this lasted probably 2-3 months) i ALWAYS cried, whenever the slightest thing happened that upset me i woul ball my eyes out. now, for abt 2 months i havent been able to cry again, whenever something sad happens, any degree of sadness, i feel like crying & lying on the floor & dyeing, but no tears will come, i feel like im bottling things up, & i get this feeling in my stomach, like a mixture of puking & heartbreak, i have heard of anhedonia, do i have this & if i do how do i get over it??