Asking me to enter a value for LINE 11 Total wages from this business related to my home office, but it is not a separate business from my W-2; what do I do?

You will enter all or a portion of the wages listed in box 1 of your W-2.

Home office expenses are limited by the income associated with the home office.  If you spend 100% of your time working from your home office, then you have earned 100% of your W-2 income from that office and you would enter the amount shown in box 1 of your W-2. 

Similarly, if you only work from your home office one day per week, then that would be 20% of the time (assuming a 5 day work week), so you would enter 20% of the income on the W-2 in box 1.