My roommate thought she hated cooking and then she moved in with me and started using knives that were actually sharp and realized cooking is fun. Sometimes I wonder how many other situations are like this. It's not you, or your skills. It's just the lack of correct tools. Everyone knows you need a knife in the kitchen but no one mentions a sharpening stone.
Also you should probably sharpen your knife.
Speaking less metaphorically I literally do wonder how many people would realize Cooking Doesn't Suck if only they had sharper knives. Cutting vegetables is not supposed to be a workout. You're not supposed to apply force when you press down. If you have to force the knife down then the knife is dull! This is a fixable problem!
you can get a sharpening stone for under ten dollars and soak it in water in like a leftover Chinese food container (the plastic ones like from the sesame chicken combo) and pass your shitty dull walmart knife* over it for like 4 total minutes of sharpening time (please do try to keep both sides even to avoid curling the edge over) and that'll be already SO much better than what you've been putting up with, I promise.
*no judgement, I too own shitty dull walmart knives that I don't sharpen often enough, that go too long sitting in the sink after using, but Occasionally Sharpening Your Knives is better than Never Sharpening Your Knives. I WILL be honest and say the noise can be pretty grating though, so if you're the kind of person for whom that would a capital B.S.E. (Bad Sensory Experience) I'd suggest putting in your earplugs or headphones and blasting some music, possibly putting on some disposable gloves too cuz of The Texture.
may I recommend, for your crap knives, for people who don't have the wherewithal to spend 4 minutes dragging a blade over a moist rock:
also available for less than 10 bucks. usually 10-20 drags of a blade through those grooves does the trick
Note: if you have some knives that are actually nice, a tool like that will absolutely destroy them. (Takes off too much metal, removes whatever good edge was already there) So the 100$ chef’s knife I was given for Christmas a couple years ago waits for my dad to visit with his actual sharpening stone, and I use the handy sharpening tool on the 6 cheap knives that make up the rest of my knife set.