dumb overused checkmate

Are you referring to Scholar's Mate?

Flip the Board

Move your kingside knight.

If you are referring to the "Scholar's mate" as it is called, where it is a 4 moves checkmate by white. Then you can go on youtube or lichess, there will some useful material for you to study how to deal with it.

The Scholar's mate is as follows:

2...e6!

After defending the e5 pawn, you may play g6 (if the queen is on h5) or Nf6 (if the queen was on f3)

just use the Hippotamous Defense

The French, the Pirc and Alekine's Defense all stop any ideas of the Scholar's Mate in short order. Or anything other than ...e5 really.

This was one of your games on 27th of November.

Obviously, your move 2. g4 is a bit peculiar. It's one of the few rare moves that loses a game on the second move. It usually happens intentionally. Even very stupid people don't blunder like this, because the move g4 doesn't make any sense, even without the mate threat.

On the same day this happened

Not as crazy as the previous one, but still quite remarkable. This was the the most telegraphed mate attempt I've seen in a while. After 1. e4 e5 . Bb5 Bb4 3. Qf3 it should be obvious what your opponent's plan is. I realize you only looked at the position for 6 seconds, but I still believe you should ne able to see the threat on the board if you bothered to look for it.

From a couple of days earlier

You played 1. h4 2. g3 3. b4 4. a4. In the meantime your opponent played 1. e5 2. Qf6 3. Bc5 4. Qf2#.  Your opponent had a plan, that may be overused but as long as your plan is the worst plan, I suggest refraining from calling their plan dumb. 

Last example

No additional comment.

Players at your rating level play like this. If you lose against attacks like this, you will keep facing them. The good news is that you can easily prevent losing like this. Opponents like this are the easiest to beat. GL!

Pawns don't go backwards!

Precisely why it's brilliant

It's only dumb if it didn't work.

I suppose this is the game we are talking about:

It is amazing to me that you think that that loss was because of the opening. In fact, it has nothing to do with the opening, it has everything to do with blundering the queen on move 20.

That said, the opening play was also bad. But not as bad as the middlegame blunders. A repeating feature of the game is that you give up material for no reason. You should probably play a longer time control, so that you have time to double check your moves before playing them.

I was alr short on time on the game vs dolphinubu

1.You could play a different opening

If your opponent plays bad moves, you resign? That is an interesting strategy for sure.

1. e6!!