strat is fine, amp seems fine.
change guitar, not necessarily upgrade, if you want a different physical feel, like weight, balance, thickness of neck, neck curvature, body profile, or even just color/look.
change amp if you need more sound out of your amp, because you are playing in larger venues and cant be heard well by the audience, or if you specifically want to try different types of amps, or needs features from an amp that other amps dont have (fx loop for example).
other things would be to try a computer-interface to try messing with stuff on software
similar but different is to try out a pedal or two to get different sounds out of what you have.
maybe do something else like get a camera to record yourself, or audio recorder. maybe a mic, or other support.