don't worry, that happens to many people who come to teach in a foreign country, if that is what you are referring to. many did not ever plan on being foreign teachers, thus paid little attention to grammar in their education, since the universities do not either. however, for the language learner, grammar is a controversial necessity. it is controversial, because so many teachers learned English without learning much grammar. but, as far as its real necessity, it does not take much logic to recoginize the fact.
this website is good for grammar, as is one other called English Page.com. but as far as anything supplementing a curriculum, i have not found it on the internet. after teaching in a foreign country, one sees how nice it is to be able to work from the excellent textbooks found in some of the English speaking nations.
as far as 5 grammar points, i would emphasize the issue of PAST, PRESENT AND FUTURE, repeatedly. some languages do not have this as a constant principle, but of course, with English, it is the basic idea of each tense. if the student can begin to learn this idea, they can develop automaticity, meaning that they will eventually not have to think about which tense to use, it will arise in their minds automatically, which is the goal of ESL teaching. being that the ESL student in a foreign country does not speak the language at home, as do first language learners, they need to practice using certain verb tenses in your presence. they want and need you to correct them, however gently, when they make mistakes. He have or he has, etc. also, being that the ESL student does not have have 12 years of heavy grammar and writing classes like we do, day in and day out, they don't have much in punctuation either.
you certainly have nice writing. just go back and study the four verb tenses plus conditionals. then, see if you can teach the idea of prepositions!! and of course, students love to learn to use adjectives, as it gives them the chance to be more descriptive.
best of luck.