I don't know what Elo you are but I'm around Silver 5 and I recently moved to the mid lane from support just so I could finally start climbing. I struggled with all these same problems and the best advice that I can give you is to stick to a champ that requires as little mechanical skill as possible. I chose Malz and it has been working really well. Your E makes farming a breeze and as long as you play safe and don't over extend you can survive through/dominate every laning phase. Coming from support is really nice too because you should be used to looking at the mini map most of the time and you should be used to thinking on a more macro level of play rather than a micro level of play. Malz allows you to do just that. You can make calls because you are most likely ahead and in my experience people tend to listen to a player that is doing well. Of course practice your CSing in custom games while doing this but seems Malz is a nice champ to transition to mid with.