After having workinged all day, although I knew I had to go to bed early, I felt empty fordue to not having enough personal time.

Since the second part of the sentence is written in past tense, I would make the gerund past tense as well.
I also think 'due to' makes it more clear that you feel empty as a result of not having enough free time.

I also don’t idn't have enough energy for my hobbies, which is why I scrolled through social media to entertain myself.

Again, make sure that the tenses match in both parts of the sentence.

I also don’t t have enough energy for my hobbies, which is why I scrolled through social media to entertain myself.

That's relatable.

Sleeping Schedule

Both work

I need to start adjusting my sleeping schedule.

Again, both work. Also same here.

After working all day, although I kneow I hadve to go to bed early, I feelt empty fordue to not having enough personal time.

I think both make sense but something like “due to” might clarify it a little more.

As an extra note, I think that your original sentence would be used more so with reference to a specific day. As in “Yesterday, …”. If this situation still applies to you now, I would use the corrections I’ve put in above.

I also don’t t have enough energy for my hobbies, which is why I scrolled through social media to entertain myself.

Make sure to keep the tense constant. Since you say “I also don’t…”, which is present tense in the negative, you should use the present tense throughout the rest of it (“scroll” instead of “scrolled”)

If you were talking about a specific day, as in if you were recounting an experience from the past (similarly to my comment on the previous sentence), you might say “I also didn’t have enough energy for my hobbies, which is why I scrolled through social media to entertain myself.”

Also, you could use “so”, or something else to indicate that the first part caused the second part, instead of “which is why”. But this is purely for conciseness.