I want to start a career in psychology , but I ...

Start by going back to school and majoring in psychology. Look for a good psychology program in your area.

Yep. You have to get your degree before anything else. Psychology is a very hard profession. People don't realize that. If you can't find a way to distance yourself from the patients, it will tear you apart. I say that being an ex psychologist. I am far too empathic. I just wasn't able to bear the level of other people's pain. I wasn't able to separate myself. So first examine yourself and determine if you are suited to a profession that deals with people's pain and emotions.

Yes You can Start Your Career in Psychology if you have interest in it. Because if you have Interest in Any field and you have Proper Frame of mind that the particular field is best for me than there is higher possibility that you find best possibilities in it...

You will need at least 4 years of college, majoring in Psychology (with most of those courses coming in the last 2 years, with the first 2 years being a diverse group of general courses, like math, science, and others).  This results in a Bachelors Degree (B.A.).

While there are jobs for psychology majors with B.A. degrees, to really do well in the field and to get into "clinical psychology" (if that is what you want to do) a Masters Degree (another year or two) and/or a PhD (Doctorate, in psychology) is almost essential.

ROB