If he is still active doing zoomies and binkies, and his eating and pooping is normal, then it probably isn't a health issue causing the change. With you mentioning picking him up and him hating it, I think that's your most likely answer. Some rabbits can learn to tolerate being picked up when necessary without holding a grudge, a rare few don't mind and like being held and cuddled, and there are some rabbits that hate being picked up with such a passion that any attempt to do so will damage their trust in you and your bond with them. And they learn to associate the approach of your hand with being picked up, and so will learn to run away from you even if you are just wanting to pet them.
So my suggestion would be to not pick your rabbit up at all, and spend time sitting on the floor with your rabbit and not force interaction or pets, but allow your rabbit to come to you. This is how you build a trusting relationship with a rabbit. Be patient, because it may take your rabbit some time to forget the fear of your hand approaching him, and trust that you aren't going to try and pick him up anymore.
https://rabbitsindoors.weebly.com/bonding-with-your-bunny.html
https://flashsplace.webs.com/bondingwithyourbunny.htm
If you have to move your rabbit around anywhere, the best way is to train your rabbit with treats, to go into a pet carrier. And for nail trims, if you can't do them without picking your rabbit up, I would suggest for now, going through the extra expense to have it done at the rabbit vets office, so your rabbit won't associate the experience with you. Then to continue to have the vet do it or learn a technique for clipping that doesn't involve picking your rabbit up.
https://rabbit.org/vet-listings/
https://rabbit.org/how-to-trim-your-rabbits-nails/
