You currently have 552 active listings and you have sold 224 items in the last 90 days. How does that compare with your historical selling trend? One thing that may be hurting you is the number of negative and neutral feedbacks you have and only time will clear that situation.
EBay is not the only game in town these days you might want to try some other platforms and venues including local venues and forums since you are in a large metropolitan area. That however may be difficult since you appear to be drop shipping a lot of your items.