Is Consulting a Psychic a Grave Sin?
is going to a psychic a mortal sin if you didn't realize it was?
Consulting a psychic or other medium is undoubtedly grave matter and thus certainly to be avoided (CCC 2116; see also 2115-17). Grave matter is one of three components of a mortal sin. The other two are full knowledge and complete consent (see CCC 1854-64).
We cannot evaluate your subjective culpability in this matter from afar, but your self-reporting sounds like there could be mitigating circumstances. In any event, seek a faithful Catholic priest in confession so that through the ministry given to him by Jesus Christ he can absolve you of this sin (see John 20:21-23). And then go and strive diligently with God’s help to avoid this sin.