If you want to carry as top lane, don't play tank.
You also got to be aggressive top lane. In your early experiences at top lane, you'll probably get punished more often than rewarded, but in the long term it's worth it. You'll be able to understand that champion's limit and it's potential. Once you learn that champion's weakness and strength, then you will understand matchup. A lot of factors that involve being successful in the top lane is trial and errors. Lots of high risk and high reward. Because you will need to be able to outplay your opponent without the aid of your jungler, no matter if that champion counters your champion or not.
You should just pick one solid champion that you enjoy playing top. Avoid picking champions just because you see them in tournaments. Just play one champion that you enjoy playing and master that champion.
Also watch top player streams.