There are like no actual methods to toughen up that i know of, you just have to exercise some backbone (soz if that sounds harsh, not trying to offend u here). I dnt know exactly what u been thru, but i went thru some pretty rough ****, and i changed in the end. The way i did it was just good old fashioned defiance. I looked at things very practically and said bugger that, that is not letting me down. if i started to feel emotional, i just thought about afghan refugees, wrongly imprisoned lifers, or our fighting men and women overseas and thought why am i being such a pussy, when they go thru so much more stuff? look at the stuff u have and concentrate on it, dont fall foul of negativity. might have made me a mean spirited bastard for a little while, but it grew me a thick skin and i matured.
soz if it sounded harsh, and i hoped it helped