I think proper sleep is important to be creative and productive, reduce stress and improve health.

I believe physical activities are the easiest way to go from here. Like you sad walking and jogging is a good start. However, you may want to look into doing a sport that you like. This is something that takes more effort and also has a learning curve which will keep you motivated over a longer time.

Besides that there is mediation which is also really nice to create some rest in the mind to be able to sleep better. Start by looking into guided meditations, you can find many on the internet. And do this maybe 15-30 min every night before you want to sleep.

Also do not underestimate a good basic diet, eating healthy will make life a lot easier for your body and regulate things. Cutting down on sugars and caffeine, drinking lots of water etc

Good luck!