Ankle, Knees And Lower Back Pain. Also Have Depression. What Can Help Me?

Hi there i have a few problems with my lover back and enkel and knees ok my back i hurt when i was a teen i fell on wet steps and fell right on my back with the sharp coners of the stair and my back gife me much more troubels now that im getting older thy took exrays and recon thy cand see any thing on the xrays what do you segest i do with my knees i fell on them with my how body wight on 1 on a hard conkreet floor it was soo painfull and red and blue thy took xrays again thy dont see any thing broken but is still very painfull and when i stamd on my knees it feel like i standing on broken glass when i run my fingers over my knee i some thing feel like hard cristals on my knee my enkels in very weak i hurt them all the time i tear the legaments more then i can remeber if i just walk a wail thy swell up like baloons im getting fores to go work and its a strugel every day of my life with pain so bad i cant consetrate even if i drink pain kielers like candy im suffering in dipresion and these problems dont help me much at all pleas gife me some good adfice thanks.