Stop playing blitz. Not good for education if you want to improve.
Every time you look at a position, do an UPS check.
UPS means Unprotected Piece Scan. Look for all pieces which are not defended, or attacked by a pawn. Also for pieces which are attacked more times than it is defended.
If you alarm blinks (one of the 3 things above is happening) try to defend. Also of course notice your opponents pieces, and see if you can make a DOUBLE ATTACK or something like that.
How do i do the UPS thingy?
When I first saw the title, I thought it was joke, kind of "I was amputated of both hands and now I cannot do push-ups anymore, why ?". I was disappointed.
i have seen people we started chess about the same time mated with a bishop,knight,the king and a pawn(the pawn did not get promoted),though his opponent had two bishops and the king only on the board.what do you have to say about that?
Those mates can be done, but they're difficult. If you look at "computer workout" under the "learn" menu, you'll see some of those available to practice.