losing streak

I need help.. i have seen a pattern in my games.. I play vel koz support.. I often get an early lead with my team.. we get an inhib we get baron etc and then we lose.. every single game.. I cant push without my team with vel koz so i often just sit mid and waveclear and w8 for my team to grp.. Any idea on how to use that time better? im afraid of getting caught in this assasin meta.. And that often makes me lose my mid game power spike.. I know everybody gets losing streaks.. but im really clueless on what to do..