HOW TO SPOIL A POSITION

I have just spoiled a good solid position by playing well i don't know what to call it.
Chess blindness or just not paying attention.
You decide.
I am white in this position.




Black plays 1..........Bc3 attacking my b4 knight. So instead of moving the knight to c2,i play 2.Ke2!!!!!!!! goodbye knight.

Was this position drawish before my bad move?

WHAT MOVE NOT TO PLAY

I have played some bad moves in my time,but i think this is the worst.



I am black in this game,doing nicely,a piece up for 2 pawns.
King in the open,but i have to protect my queen side pawns.

I am not sure what happened but i played Re8!!!
White can take the rook as my knight is pinned.

Is this chess blindness or very careless play,or both?