I had a long round of prelabour with my third baby too. It really stinks to go through - emotionally and physically so tiring! But, you can remind yourself that every contraction is doing something - even if it's not the "real thing" it will help to get your baby in place and get your body ready. When real labour starts, it will probably be fairly quick.
Rest when you can and distract yourself! Plan some nice things to do - pedicure, manicure, massage, hair cut, new book, lunch with friends, knit or crochet or paint or sew something for baby, design a birth announcement.... whatever.