Pick your favorite obstacle to skate: slappies, manny, tranny, etc. and design a session around that.
I recommend a skatepark at a quiet time as the ground is smooth and tricks are easier to aquire or relearn.
If you are more on the introverted side, go at a quiet time and bring some nice music to get the hype flowing.
Also, remember change is inevitable. I don't skate 3 hours a day everyday like I did when I was a teenager, and that's ok. Even in smaller doses, it is the still the same fun wooden toy and always will be.
Going through peaks and troughs with skating motivation is normal as adult responsibilities take hold.