It's normal for young children to cry at drop off to preschool. Nothing you have mentioned in your question has suggested tome he is a strong willed child, he's being a typical 2 year old who is adjusting to preschool.
I have taught preschool in the past, and I would suggest you drop him off, say your goodbye and leave promptly. I know from experience that the children may cry for a few minutes, but will settle down quickly after the parents leave. The more prolonged the goodbye, the harder the transition is for the child, really. I would give it several weeks before pulling your son from the program, because three days isn't sufficient time to allow him to get a feel for the routine of preschool. If in a month or two, you really feel he isn't getting the hang of things, you can pull him from the program and try again at three years old.
It's great that you are speaking Portuguese to him at home, I encourage you to keep doing that. Now is a great time to introduce him to English too, because children's brains at this age are like sponge; they soak up everything so quickly. You can try introducing him to English in other ways, like story time at the library, or a drop in play group, or a Mother's Day Out, or a Mommy and Me class.
Good luck in whatever you do! Just remember you are a GOOD MOM! :)