Don't make the mistake of thinking you have to push your lifting so hard that it is detrimental to your sprint performance. If your coach has a record of producing good sprinters don't worry about it and just do what he says. Weights are a means of general preparation for sprinting and so should not take precedence over other more specific activities in the the program.
If your weights have dropped since training with the team it's possible you just had too much emphasis on strength work before whereas now you have a better balance in your training. In-season lifting shouldn't be particularly intense, the priority is on speed work at this point.
If you do wish to find a coach to help with your strength training whatever you do find someone that works extensively with track athletes, ideally a track coach who is also strong on the lifting side. Weight work needs to be properly implemented in accordance with the rest of your program and someone without the experience stands just as much chance of messing up the rest of your training as helping you.
Have a look at the forums and materials at charliefrancis.com if you want to learn more about training for sprinting.