thanks all of you who helped me a lot .it was wonderful to be here and got nice people to reply.
I brought new rx 570 works wonderful no more black screen no freezing. Thanks once again.
https://linustechtips.com/main/topic/844139-black-screensignal-lost-after-gaming-for-awhile-with-rx580/?do=findComment&comment=11223252
Is this helpful..