Is it possible that the gears switched from left to right? I'm 100% sure that my gear levers on the right side are for my front gears and the ones on the left side are for changing the rear gears. 

After a muddy ride today it seemed that this changed. I was pressing the right levers to change the front gear and the rear gears started to change instead. 

Is it possible? I know I have to take it for maintenance, but I wanted to check before so that the guys there wouldn't think I'm crazy. 

My bike is Giant ToughRoad SLR GX 3 2018 and I had it for about 8 months during which it didn't have any issues.
The standard setup is left for front and right for rear for gears. 

For gears you would need special left rear and right front shifters, which are not manufactured. It is very unlikely that you had those, and they converted to normal shifters during one ride, at the same time as cables rerouted themselves.