Is this really a blunder?

Hi Guys!

I've been learning chess alot and i have been watching top 5 Brilliant moves on youtube at chess.coms channel,

it really opened up my game in ways i haven't thought of playing pieces before
I have been recently trying ways to sacrifice pieces to get an advantage,

what i would like to know was this really a blunder,

my move of Bbc1 > Bbg5

and the chess.com engine says the best move after that is black pawn capturing the Biship on the g5 square.

I got the checkmate soon after I did this move with the king moving in to C6 after i checked him with the Queen Qb3 > Qh3

Any Analysis would be a big help to my game and I would like to say thank you in advanced!

Thanks!

Woah thank you so much! i haven't seen that line at all, the possibilities of chess is truly amazing

It certainly was a blunder, you gave away a B for no apparent reason. If after Qh3, your opponent moved Ke8 instead of the (blunder) Kc6, your advantage would have disappeared and once your opponent got to develope, you would've been losing. 

thank you very much for the insights

was lucky i still won with the blunder!