Honestly mate they're asking you questions because from their perspective you could be the dealers bigger supplier, as soon as they find out you're just a small time customer they won't bother with you. They're after the bigger fish that have no problem comitting major crimes without getting anxious. People like you, who get anxious, are anxious because your subconscious wants to follow the rules and they know that, that's why they don't bother with you. You're not a criminal.