I feel like everyone else is better then me, and I'd like advice.

I've been playing since 2011 but I feel like I've been lagging behind for some time now. I've never been higher then Silver 3, heck I'm Bronze 1 right now, and I usually lose lane. My most common roles are support and jungle, and I'm not very good at jungling. It's difficult for me to make quick reactions because I have motor coordination problems, which is why I avoid champions like Lee Sin or Ekko or others that require fast reactions. What are some tips to get better? Any advice will do.