Hi, I'd like to help you with your question.
An increase of 10 mg should not have that much of an effect as to make you emotionally dead. Most likely, it will just slightly increase the side effects that you have already had on Paxil. I have heard of patients taking up to 50 mg and they report feeling an increase in tiredness but they were still able to do their jobs and activities.
Go ahead and try the 20 mg and see how you feel. Give the medicine at least a week to take effect. If you find that you feel worse, call your doctor and ask to decrease the dosage.
I hope this helps,