g-pawn on the move

This is my first post, so here is a few facts about myself to start out with. I'm 49 years old, and restarting my chesslife after having been away from the game for 15 years. I only reached a 1095 ELO-rating back then, so I'm not the next challenger for Magnus Carlsens title. But I like chess, so now I'm starting out again.

In the game above I tried to play the Colle opening, but everything went terribly wrong from the start. In the Colle-games I've seen so far, the g-pawn never come racing down the board, so I was completely unprepared when it suddenly happened.

How would you have handled this respons from black to what should have been a standard Colle-opening, but ended up a mess?

Simply 5.Nd3 and his whole kingside is looking pretty sketchy. You can consider attacking the pawn with moves like Be2, h3 etc.

But even earlier, why not just take his g pawn with 3.Bxg5? It develops another piece even whilst gaining material.

You shouldn't just play for the same setup against every Black move. Try and look to see if you have something better!

Thank you for your advice. I never even considered taking the pawn, because I was completely focused on establishing a position according to the textbook. Instead I should have reacted to what was put in front of me instead of insisting on holding on to a mainline. I'll try to remember that.