Playing too fast is an obvious weakness:
A 10+0 time control game with 8 minutes left on the clock when it is over, i.e. played as if it were 2+0 bullet.
Apart from the blunder, there is also a strategic error Bb5xd7. Your Bf1 is your good bishop, not on the colour of your pawns, Bc1 is your bad bishop on the colour of your pawns. Likewise Bf8 is his good bishop and Bc8 is his bad bishop. You trade your good bishop for his bad bishop. Moreover you give him a tempo. Bf1 and Bc8 disappear from the board and he gets the developing move ...Nxd7 for free.