The last piece of advice that I have before you start selling on ebay in earnest is to take a day off. As you work on your selling schedule, try to fit in some fun activities that take you away from a computer and from the world of eBay. When you return to selling you'll be refreshed and raring to go. Most eBay sellers that I know are workaholics and one person shows. So it's important to be able to ask for help when you can. Step away from the computer.
Get outside of nature, take a walk, go for a swim, take a bike ride, go to a ballgame. This practice works for me. I usually take all my Sundays off, and I rarely ship eBay items on the weekend. One of the great things about eBay is that there are many things that can be Automated, like leaving feedback. So you can keep working on eBay even when you're not there. What other place can you actually make money by not being present?
Or maybe even while you're sleeping. eBay is one of those places. Now go take a day off