Can I get rabies from a tiny scratch of kitty in my finger? No rabies vac given, only tetanus. That happened 3 years ago. Please help

No rabies. Rabies would have manifested within a few weeks if you had contracted it. Since the cat scratched you three years ago, and you did not experience any symptoms, you did not contract rabies.
Rabies risk. The scenario you described carries an extremely low risk for rabies. I would try to calm your fears.