"Wearily" is already an adverb, describing the manner in which something is done. It means "in a tired or exhausted way."
To express a greater degree of weariness, you can use adverbs like:
* More wearily
* Extremely wearily
* Exhaustedly
* Drained
* Fatigued
For example:
* "She walked wearily down the road."
* "He sighed more wearily than before."
* "She looked at him exhausted."