Perhaps a few things need to be clarified. For example, OCD is an anxiety disorder, so you don't have two diagnoses but one. Second, I don't know how you came to the conclusion that after only two appointments this psychiatrist knows you thoroughly. It would seem to me that it would take a bit of time for two people to get to know each other very well. Of course, I may be wrong and you may feel that she does totally understand and know you.
Since you are 22 years old, you are a bit out of the "child and adolescent" range and you might want to ask how many young adults she treats since this is an important factor in therapy. Certainly, this is quite a different stage of life than when someone is in their teens. I'm assuming that you may have been referred to her by someone else and that's how you came to make the appointments.
Medications can be quite helpful, but it is my belief that the most conservative approach should be taken before considering medications. It may be that you do need medication, but I think this needs to be determined after you have had sufficient interactions with a licensed psychologist or other appropriately licensed mental health professional. It is the usual case that diagnoses are, initially, what are called "working diagnoses" until there is enough information to arrive at the final diagnosis.
Many people do have problems with medications and, in fact, finding the appropriate medication that will work best for anyone is always a trial-and-error process. There are no medical tests which can determine the medication that would be best for anyone or even for anyone's specific symptoms.
You have to make the decision regarding whether or not you will follow this psychiatrist's recommendations regarding the medication she has prescribed. It is your decision and you need to make it after being fully informed about both the benefits and the possible side effects. I see that you have done quite a bit of research on your own and that's a good thing. Being an informed consumer is the best way to proceed in anything.
I hope that things do work out well for you and that your therapist and you can work effectively on the difficulties which you are experiencing.