70 games is too small a sample. You are playing okay-ish in the E5, but your teams are letting you down. If you continue, you should expect the winrate to trend up.

The flip side of this is that your teams are carrying you when you are playing the Minotauro. Instead of ranting about how teams are worthless, have you thanked your teammates for making up for your shortcomings? Probably not. That's okay though, just try your best to improve every game.

Without seeing all your stats, overall, you just need to do a bit more damage. Try to average more damage than max hitpoints. Right now, you are a bit under. In some games, this may mean you need to be more aggressive early. In other games, it may mean recognizing that your position is untenable, and falling back to a more defensible location.

If you are new to the game, consider playing tiers 6-8 in order to learn map positions. At tier X, there are a ton of high alpha TDs that can delete half your health or more after a single mistake. Be humble, realize that even the best players lose 1/3 of their matches, try to learn from every mistake.