Try Home Depot or any place like Ace Hardware or local hardware store. Take in a sample of the seal if you can. I think I found some special seal for the shower door that I needed at the Home Depot and it was in the hardware section.....if I remember correctly. I believe it was in the section where the replacement parts for doors and sliding doors, cabinets, etc are located. Mine may have been like yours, and I searched at Lowe's with no luck either. Then one day wandering thru Home Depot, I looked around and I saw exactly what I needed to replace the seal. Bought 2 while I was at it and put one away for later, so I wouldn't have that issue for a few more years! Hasn't leaked since and it made the wife happy!