Keto diet

So.. i need to lose weight and nothing has worked for me I fail every diet so I wanna try this because it’s not completely eliminating all unhealthy foods. So

Can I drink diet pop on Keto?

I heard there’s a way to do Keto wrong and actually gain weight, what would be considered the “wrong way”? I really don’t wanna end up gaining more weight.

Also, did it work for you? How much weight have you lost?