Ride with people you like and have fun with, ride a horse you like and do fun things with it. Discover a new way of being with your horse! And if you truly are passionate about horses, you will come back to them eventually. (My sister is depressive so she stopped riding for a while, but she couldn't stop forever. She loves horses so much.) In my opinion liberty groundwork is great as it lets you find a new way to enjoy yourself with your horse, and you build a very strong relationship through playing together.
riding is supposed to be fun- so do fun things! go swim with your horse, ride with friends, just go love on your horse. put yourself in a pressure free zone where riding is just fun and happy until your motivation comes back.
Find a fun group of people to ride with to get you motivated again. Go on fun hacks. Try new things. Stay away from shows for a good year. That helped me A lot. Got into hunt pacing for a year and it helped rebuild my motivation because it was fun. And that is what riding should be. Fun for you and your horse.
I agree with Savannah and Ryan
You could try an other discipline and ser if that helps.
Take a break if you need one. Maybe don't ride for a little bit but still come out to the barn and groom and do some fun things- teach your horse tricks like smile, and to pick up their hooves on command. Or try something new- go trail riding if you don't ever ride outside the arena. Try your hand at barrel racing or reining or western dressage or trail of you always ride English, and vice versa.