As someone who has experienced this firsthand, i can say that debate definitely isn't a very strong ability of mine. Yet still i find a lot of interest to go to muns but I've been considering only press comms for the ones im registering in.
I assume you mean you have a favourite committee that was your strong suit, that is turning into a weak suit coz of better delegates. Happens all the time. When I used to delegate in the UNHRC, it used to be a cakewalk with around 3-4 best delegates in a row. Before I took a break, then came back to a fiery competition in a private mun. It's all about learning. If someone beats you, follow up and learn from them. What they do, what their thought process was. You can be humble enough to talk to them and see if they did something different from you did, and see if their plan of action gives better results for you than yours. Then incorporate their's into yours and benefit from it. Giving up should be the least of your concerns.