two years is a very short time. if you haven't found your fluency, as you say, it's perfectly normal. it takes years to speak another language fluently, and it happens if you (in general) put in an enormous amount of work and dedication, in other words, if you have passion. same with playing an instrument. even a virtuoso keeps on practicing hours each day, they don't beat themselves up for it.

we often hear, read, about how to speak a language in six months or less. it's a scam and a lie. plus, as i see it, learning a new language is about enjoying the process of learning just as much as reaching a good level. the learning process is underrated in a society where everything is fast-paced, you have to become excellent at many things in as short an amount of time as possible. it kills the fun and makes people feel bad about themselves.

the journey is its own reward, the destination is an illusion (like the horizon which recedes as you walk toward it), because even when you are fluent in a foreign language, there always remain things (words, expressions, and a degree of fluency) that will elude you. even in your own language: you constantly learn new words, check your conjugations (i sometimes check my conjugations in French) so why not just enjoy the journey and take the time to admire the scenery?

Well, some people consider the grammar easy to learn and others do not. On the other hand, the hardest part is the pronunciation (at least in my opinion), it's even harder if your language has a much different pronunciation.

As you speak Portuguese, you're kind of lucky, because the pronunciation is not THAT different. You need to learn how to make some new sounds and how to link the words. Some people learn it fast while other people learn it slower.
Don't be frustrated about your learning, the more you learn, the more you'll THINK you're not having progress at all, when in fact you are.

As for the native speaker part, I don't think you need to speak like a native to be good at English, you just need to speak clearly and confidently. If the person you're talking to can understand you without many difficulties, that's enough. You don't need to sound exactly the same as them.

But anyway, everyone has a different way to describe "being fluent at a language". If being fluent at English for you is speaking like a native then go for it. It requires hard work and practice. Practicing is the key to achieve your fluency.

Don't let anyone put you down by saying anything bad about your language skills, no one is born knowing how to speak. And besides, you're learning it by yourself. It's not like you're just trying to do the "1+1=2". And as I can see, you're good at it.

Give yourself some credit for that, no need to feel frustrated. Keep learning :)

I'm a native speaker of English, and I would never call English easy!  I don't know why anyone would.  English grammar has many irregularities, English phonetics are hard to predict, and English spelling is so complicated that native-speaking children have competitions to see whose spelling is best!  Many - perhaps most - native English speakers don't understand things that they should have learned in elementary school, and there are even more rules that few people other than professional writers, editors, and teachers know about.  So, please don't think that you're the only one having problems!  I promise you're not alone.

But, don't let this discourage you!  If anything, it shows just how many mistakes you'll be able to make and still seem like a native speaker.  If the native speakers don't understand the rules perfectly, you don't have to understand them perfectly either!  :)

People say this about every language I've learned, so I just ignore them.

I have no idea why people say things like "English is the easiest language to learn". In my life it is commonly said by those who never had an experience of learning of any foreign language. I've been learning English for the last three years and I still don't understand it good enough.