There's a lot of great advice here, as I'd expect. One thing I can add is, you have from what I see a pretty decent 1 m power, esp for a cat 5, but you didn't list your 5 - 10 s neuromuscular output. If you have a really good 5 - 10s jump, one more thing you can try is, depending on the course, pick a good spot early on the last lap to jump hard early and see if you can pull a minute+ hard to the line in front of the pack, instead of forcing an early break. Spend the bulk of the race sheltering and saving. You know a break won't stick so let others chase them. My experience in cat 5 races is there isn't cohesion on the last lap, and leading up to the sprint, no one works together well and people are antsy and half commit to the sprint too soon, in that in between time of about 150 - 200m out, that's probably too long a sprint for most people at a typical cat 5 fitness level. Watching the 3's and the 1/2's race, the pack seems to stay together more until the sprinters know they're in range of the line so they don't get gassed 10 or 20m out.
Also, watch as many sprinterdellacasa youtube videos as you can and read his advice in the subtitles. That alone will give you a leg up on the average Cat 5.