Is there a way I can get myself to enjoy things again without therapy or medication?

Its gonna sound easy or irrational but you need to do things that trigger dopamine and other feel good receptors in your brain... working out releases high doses. Being surrounded with good people that motivate you or you can look up to. Try stepping out of your comfort zone and do things you wouldn’t normally do. maybe you could be lacking important vitamins and minerals. Things like vitamin D and the sun actually help you fee better. Try volunteering in your local community, helping others that are less fortunate can be very gratifying as well. I hope my suggestions will give you some guidance