Hi, I have been suffering from severe anxiety and depression / anhedonia for about 3-4 years now. I have always had anxiety problems and maybe a low?

Therapy? Have you yet tried any form of psychotherapy? Typically, the optimal combination of things to treat emotional issues such as anxiety or depression is medication (which, on your best day, is supposed to take the edge off symptoms) but the real gruntwork takes place in psychotherapist's consulting room.