everyone makes mistakes - don't bum yourself too much.
If you want actual tips:
look into the line 4...Nc6 5. Nf3 d6 6. Bc4 a6 7. 0-0 Nf6
13...d5 looks safe: 14. exd5 Nxd5 15. Nxd5 Bxd5 16. Qd3 g6 and Black develops easily.
14...Nc4 is pretty darn aggressive: 15. Qc2 Qb6+!? 16. Kh1 Ne3 17. Bxe3 Qxe3 and I think Black is safe
But at least you learned a new tactical pattern. Don't give up chess because of this!
A important standard (15min/10) tournament game here on chess.com I was already guranteed 2nd but to get 1st had to win this game and well....