Retro fit and part swap, or NBD?

Been thinking nonstop about getting a new bike and selling my current. Not after crazy upgrades, just better fit for better experience (though hydro brakes don’t hurt…)

Current bike is a Giant Contend AR 4, size medium. I’m 5’5. I bought it last year and it’s treated me mostly well for the type of riding I do (anything from short rides around my city, to 50+ mi rides on crushed limestone gravel).

As I ride more, the fit issues become more of a problem. Some days are worse than others, sometimes it’s not a problem at all. Lately it’s been annoying me (knee pain after 10mi, hand discomfort/ chaffing on the palms from pressure. I generally switch between drops and tops every minute or so. I have a goal of doing a 300mi rail trail this summer and don’t want to deal with injury getting in the way of a journey.

Unsure of what to do. Torn between one big purchase of a new bike, or a bunch of smaller purchases to make this bike fit.

TLDR: should I try and retrofit the bike to make it work, or sell this one and get a new bike that fits me properly?