The GIMP is not Photoshop, and although they have visible similarities, there are obviously a lot of differences too. When I was using Photoshop on a daily basis many years ago, it was what I got used to and my transition to GIMP had some utter similar to the OP, "I cannot work with it!"
A pivotal moment when I completely dropped the other OS along with apps that work with it, including Photoshop was a very hard decision to make but I really couldn't live with Windows anymore after a mind-opening revelation that Linux does more.
So unless you listen and follow rich2005's advice to "Live with GIMP", I hate to say it but I guess you're stuck. You might as well boot Windows and run Photoshop. I've also heard rumors (or maybe they're facts) that the GIMP devs are working on a release that would be just one class of windows, giving it more of a Photoshop look. I'm not really keen on it.
I can handle GIMP... Photoshop is still a familiar app but if I would choose which one I'd use, I would have no hesitation in choosing GIMP, with my eyes closed!