discharge

For the last 3 years I've had this yellow-ish discharge every day. I have to wear panty liners and change them several times a day. Sometimes it's sticky, sometimes not. But it's smell is terrible. I've seen 3 different GYNs, tested negative to all STDS/infections, and they have no idea what it is or why it happens. No medication or home remedy will clear it up. It's embarrassing and just gross. I feel totally alone and not sure what else to do but deal with it.. anybody experience this? Or knows of a Specific GYN I should find in my area?