Track events?

I have a track meet coming up in two days. We are only allowed to compete in 4 events each meet. I have Javelin, 100m, 200m, 100 HH, and 300IH to choose from. I need to drop the 300 hurdles or the 100m. I really want to try the 300 hurdles because I've never done it, I've competed in the 100m at almost every meet and only got about 14secs, and we don't have many more meets left. but the 300H are right after the 200m and my coaches were telling me that would be haaard. I wanna do it but if it's impossible than maybe I shouldn't. Would this be too much?