Unexpected disconnects and whole PC freeze

I have passed a map with high % rarity,after what i decided to clear breach in that map,game lagged and everything stopped,threw me back to character select menu and map showing as attempted.And also,game freaakin freezes whole PC on loading screen constantly and you have to force shut down it.PLEASE do something about it because it is getting annoying
And just noticed,all my collected stuff isnt in my inventory also.