I'm Having Trouble In Comp As Venom

So i started playing comp again after a while and I'm gold 1 (very low i know), but i genuinely can't seem to push up. I win 2 games then lose 3, I'm a tank main: angela, venom, peni.(preferably venom)

It just feels like I can't kill anyone when i play venom, especially when there is a invis, gambit or jeff. I basically feel like a useless ult battery because when i do kill the supports my teamates are dead and then I'm left alone being useless again.

I also really struggle to hit my shots sometimes, the rhythm of venoms weird attacks is hard to get the hang of. I also struggle with knowing when to dive and when to frontline. I really do like venom but i might have to drop him because of me struggling to get that much value out of him. Oh and peni is banned 24/7 so i only have angela and Emma to switch to.

Any advice on how to actually do something with venom?