Trouble equalizing below 12 to 13 ft

I hope someone here can help. I'm in Bonaire this week to finish open water certification and beyond 13 ft, I have a hard time equalizing. Both of my ears hurt, no matter what I do to equalize, it just doesn't work out. I start to hear buzzing and there's pain associated with the buzzing.

Decongestants and sweet oil for lubrication have not helped. It seems like I will go home empty-handed and have to finish this open water certification later on in life. To get more time in tomorrow and to be a bit more productive, does anyone have any suggestions that I haven't tried yet? Equalizing by pinching my nose, turning my head side to side, stretching my neck, swallowing, burping, nothing seems to help. Last night as I slept, and got up, I noticed that my left ear still hurt, that told me there's a problem. Anyone else go through this? I'm not ready to give up on this venture yet. This has been a long time coming.

Thanks for everyone's advice,

Steve