How long does it take to become an actual psychology with a high enough degree to become a therapist

To call yourself a "psychologist," one must be licensed. Licensure involves passing a national examination PLUS time in supervised practice by someone who is already a licensed psychologist. Since each state regulates licensing, the amount of time for supervised practice both before and after licensing, varies. Thus, one must know the requirements of the state in which you want to actual practice therapy. To qualify for the licensing examination, you need a terminal degree, that is either a Ph.D. or a Psy.D.

How long does it take to get to that? Here's a best case timeline:

Four years to the B.S. in psychology.
Five-to-six years in a doctoral level program (generally in clinical psychology...again, the requirements to sit for the examination will vary by state). The last year of the doctoral program in clinical psychology is an "internship" year.

Thus, the amount of time is a minimum of nine years, and may be 10 or more years...it all depends on the student (whether it's a Ph.D. program or a PsyD program and the amount of time to complete the dissertation and whether or not the student actually finds a suitable internship on the first try.

Not all therapists have a doctorate in psychology, however. There are master's level therapist (in social work and in counseling). The crendential for offering therapy is generally something called a "Licensed Professional Counselor," or LPC credential. This credential generally requires a master's degree an additional coursework to meet the licensing requirements of a particular state. Go to the website for the American Counseling Association to find out more information about this credential.

A psychologist is a social scientist who is trained to study human behavior and mental processes. Psychologists can work in a variety of research or clinical settings. Psychology degrees are available at all levels: bachelor’s, master’s, or doctorate (PhD or PsyD). Advanced degrees and licensing are required for those in independent practice or who offer patient care, including clinical, counseling and school psychologists.

PhD programs in clinical psychology emphasize theory and research methods and prepare students for either academic work or careers as practitioners. The PsyD, which was created in the late 1960s to address a shortage of practitioners, emphasizes training in therapy and counseling. Psychologists with either degree can practice therapy but are required to complete several years of supervised practice before becoming licensed.

A psychologist will diagnose a mental disorder or problem and determine what’s best for the patient’s care. A psychologist often works in tandem with a psychiatrist, who is also a medical doctor and can prescribe medication if it is determined that medication is necessary for a patient’s treatment. Psychologists can do research, which is a very important contribution academically and clinically, to the profession.
A therapist is a broader umbrella term for professionals who are trained—and often licensed—to provide a variety of treatments and rehabilitation for people. Therapists can be psychoanalysts, marriage counselors, social workers and life coaches, among other specialties. A therapist’s goal is to help patients make decisions and clarify their feelings in order to solve problems. Therapists provide support and guidance, while helping patients make effective decisions within the overall structure of support. When selecting a therapist, their education, licensing and professional credentials should be essential considerations.

Therapist vs. Psychologist Checklist

Psychologists:
Have an advanced degree in psychology
May do research or therapy
Diagnose disorders or problems in their patients/clients
Determine appropriate treatments based on clinical diagnoses and observations
Often work in tandem with a psychiatrist
Help patients/clients make decisions and clarify feelings
Provide support and guidance

Therapists:
Can include psychologists, psychiatrists, marriage counselors, life coaches and social workers
Can have any number of degrees in a variety of disciplines, including a master’s degree, PhD, MD or certificate in fields such as social work, substance abuse, clinical psychology, psychiatry or family counseling
Help patients/clients make decisions and clarify feelings
Provide support and guidance

Just to tag on...
It is important for you to first determine what area of therapy you would like to enter before heading into a college program. For instance if you would like to be able to conduct psychological assessments - depending on the state - the LCPC/LPCC and Psychologists are typically the only ones able to give these tests. If you want to work with Vets at the VA they typically hire Psychologists and in some cases MFTs. If you want to be in private practice there are 4 types of licenses that provide you the flexibility to do so. Check with your state to determine full qualifications, however here is a brief comparison:
License - Degree Level Required - Typical Post Graduate Training Needed
MFT - Masters - 3000 hours of supervised practicum/internship
LCPC/LPCC - Masters - 3000 hours of supervised practicum/internship
LCSW/LSW - Masters - 3000 hours of supervised practicum/internship
Psychologist - Doctorate - 3000 hours of supervised practicum/internship

4 years undergraduate, 2-4 years Masters, 3-6 years Doctorate, 2-4 years of supervised practicum/internship
All licenses require passing exams at local and or national levels.