Generally speaking, drugs are used by the purchaser on themselves. Outside of suicidal tendencies (which you've already addressed with mental health reform that I agree with - something that will naturally address both the drug abuse and gun violence problems to great extent), most weapons are typically used against others. They are NOT equivalent.

I don't know why you should legalize that? What's even your point?

I get what you're saying, but you're comparing apples and oranges