I can't believe there's 7 pages and these have only been mentioned once. They come in Small/Medium/Large. Many dive shops have 'em. They're cheap (under $20). For $30 you can get 3 sets, one in each size. Then you just ditch the two that didn't fit and you then know which size fits you. DOC'S PROPLUGS: VENTED EAR PLUGS COMBO PACKDon't buy them at a drugstore. They need to be fitted. Call your local dive shop and see if they carry these: BEST DIVING EARPLUGS | DOC'S PROPLUGS
I've never really had problems equalizing, but my wife struggled a bit until she got these things. They're great! They're also cheap enough that if you lose one, replacements don't break the bank. Stick these things in your ears before you splash, and equalizing becomes a good deal easier.
That said, lots of other good advice already in the thread. Equalize early and often, clean yer ears, etc. Given that you did like 10 dives with no equalization problems, I would think your ears are plenty suitable for diving. You might have a temporary problem like an infection causing you extra difficulty but you already know for sure that you CAN do it!
I don't sell these (or anything else for that matter), but I'm the husband of a happy proplugs customer.
P.S. they sell vented and non-vented. I'm not sure what the non-vented are for - you want the vented for diving. Non-vented would be dangerous to use on a dive.