I would work on weights, doing plyometrics; these are fast, explosive movements that prepare your body for sprinting better than normal bodybuilder-type weight training. Common exercises include RDLs, cleans/power cleans, and full/half squats. There are a number of good programs online that you can find, just make sure you research a variety, figure out what makes them work, and see if you can combine the elements you like. Also particularly important for 110H is flexibility, I would try and seriously practice stretching something like 4 times a week (although my muscles tighten up a lot). Ideally, you would like to be way better than hands touching your toes and have good hip mobility. If you have access to any hurdles in the offseason, keep up with hurdle drills and even implement some of the things you guys did at practice during the season. If you think technique is your problem, this is your go-to. Even without hurdles, you can still go to the local middle school track and try to practice starts, run some 30-60 meter flys to work on speed. Then, if possible, I would try and film myself some practices so I can see what I look like (for example, if you come out of your drive phase too quickly after your start, you can notice that on film).
The athletes who make the most growth are students of the sport. Right now it is difficult to say what your time potential might be, just put in consistent work to become more explosive and flexible while working on your technique too and you should definitely be south of 19 seconds next season. Good luck!