Can my crushed finger injury from five years ago still not straighten and sometimes get stiff? do i need surgery?

You have to go to a hand specialist, an orthopedic surgeon for an x-ray and exam. If surgery is necessary you will be told. Don't wait any longer. more damage is possible.

This should be evaluated by a hand surgeon for a through exam and x-rays. As a hand surgeon, I can tell you that it is often very challenging to correct something that has been present for 5 years. Definitely worth having it evaluated though to see what is the underlying problem and whether anything can be done about it.