Depends upon you.

Working.. I mean WORKING in therapy CAN change many things and mainly HOW we think about things... in a short period of time (see cognitive distortions.)

If the issues are that ingrained though, while you can learn why you think the way you do, and learn how to change your thinking, it will take YOU many years to get it down to a science to do healthily, imo.

You might not need a T for all that time.