is the cfa institute cirriculum enough?

It’s definitely possible – many candidates pass using the CFA curriculum. However if you find that it is difficult to use, you might want to try a provider. Hope that helps!

I’m in the same boat. I’m only using CFAI materials, but I’m using Investopedia’s quizzer for supplemental questions.

Of course the CFA curriculum is enough. It is produced by the organisation which is conducting the exam. If you can completely cover the curriculum it will be enough.