Even if you get countered just play passive and farm sooner or latter you will get kills, if you are getting killed often get a Giants Belt and you will pull it around, teemo is a great top because sustain has been nurfed and he can dish out a lot of dmg

These runes make it so you not soooooo squishy u get your armor ap and mr with attack speed all good for this build and in general teemo

Teemo can make shure the opposing Adc is out of the fight all he has to do is blind and auto attach him or her and they die, leaving your team up with more dmg and an adc that shouldnt be getitng touched, also shooms every were are annying for the opposing team in there jungle and stuff makes sure they would or could have low hp for fights and also easyer to catch people out then