One of the things that helped me was to put UFO's, kits, uncut projects together in tubs which I labeled numerically (1. 2. 3, etc.) wrote down what was in each one and typed out on a master list of each tubs contents and where I stored the tub if not in my sewing room. Then when I want to work on a project I can find it quickly without wasting the time to go through all of them. When I finish that project I mark it off the list. Seeing all those crossed of projects makes me feel good. If I need a gift for someone I read my master list to find something to make before going to the store to buy something I may already have that would work. I used to keep my fat quarters on shelves that I had to keep moving around to find a color I wanted. After a car accident and hurting my ribs it was painful to keep moving those stacks. Now they are in drawers standing up in one level, sorted by color, two to three colors to a drawer. I can open the drawer, find a color I want quickly and easily. I don NOT allow myself to buy anymore FQ's unless there is room in the drawer for that color. I also have a drawer system for scraps by color. When I need a small amout of fabric for a BOM I go to the scraps first, then FQ's. Yardage is stored on shelves standing up like books; easy to see, easy to get to.
I did all this in half hour increments starting in one section of the room at a time. I started by the door and worked to the right.
Good luck. It is easier to feel like working when the space isn't overwhelming.