Sounds like you're casting into a lot of structure. I'd idle in or use a trolling motor to get within casting distance, and then try casting. For lures, - I'd go back to what got them last year, and try that again. If you're losing a lot of lures, then try going to a set up like spinner baits in different colors and blade widths, these hooks will often bounce over logs and weeds. If that's not productive, I'd try rubber worms on a Texas rig with a cone shaped sinker. This setup is nearly weedless.
Only question I'd have is were the trout hitting near the bottom, or midwater? That might determine the setup or style of retreive. Good luck!