Should I switch roles?

I've played offense and hitscan characters pretty much since the start of closed beta, but coming into overwatch from an rts background without any significant fps experience I have started wondering if something like the tank role might not be better. My aim has definitely gotten better but I feel like I really lack consistency with it compared to other players and I've been finding it harder to improve lately. I enjoy both roles but I am just unsure whether it would be better for me as a player in the long run to switch roles to something more intuitive now or for me or to grind it out on more aim-dependent characters.

definitely consider switching since all of the top-tier dps players have years and years of FPS experience on you

Don't let people tell you what to do, and then do it. Play what you want to play with the intention of achieving the potential you know you can. If your going to half-ass some days, consider playing tank/support but in the end, you need to do you.