PSA: Don't play Fiddle Support, it does not work.
Ladies and Gents, fiddlesticks support does not work.
In theory, it sounds like it could work, a possible 2 second fear along with an ability that silences? Sounds great. Here's the thing though, he provides no healing, no peel beyond those two abilities, is incredibly immobile, and extremely squishy. Whenever I see fiddlesticks support that team almost always loses, or they at least always lose bot. Why? Because you have to hope that your enemy is brain damaged in order to successfully pull off fiddle. If they allow you to drain them, then they were going to lose that lane anyways for being dumb. Fiddle has clearly defined times when he has power. If he blows his fear all in him, if he uses his drain all in him. If he stops to drain CC him, if he is mispositioned from his adc all in him, there's a literal crap ton of counterplay options that make him incredibly weak in a 2v2 situation because he is so immobile and squishy. If you want an ap champ that does magic damage play Lux, Sona, or Annie but stop playing fiddle, you're throwing the game for your team.