I been learning about boundaries and self-definition a little lately. It sounds like you might lack boundaries. Like if someone says You want to do coke? you hear Do coke
You want to buy this? you hear Buy this
Do you trust me? you hear Trust me- and you act on the abreviated message- so first put the message back into a question and then ask yourself the question and wait for the answer.
Thats what I'm trying to teach myself to establish some boundaries for myself right now. I hope this is some sort of help.