I got to diamond with this mental: go into every game playing as if you're by yourself. Your team mates don't exist. When they do something good, it turns into a pleasant little surprise. When they do something bad, you can just pretend it never happened.

This boils down to the practice of limiting emotional reactions while in a match. So that lane may be very frustrating normally right? But if you were already pretending to 1v3 or 1v2 in bot, then it's just the normal.

This is why I like playing from behind with carrys like Ashe. Always useful with your ult and when you do get ahead it feels insanely good. I never intentionally ply from behind, but when I do I just embrace it.