Ever since my mom passed i've had severe health anxiety thinking i have every disease out there with any symptom. it's ruining my happiness/depressing?

Sorry for your loss : Losing a parent at any age is difficult. Being so young makes it even harder. What did she die from? Your fear of getting sick is probably your unconscious mind's way to let you know your grief work is not finished. Anyone could benefit from some therapy to help them cope with the loss of a loved one.Speak with a psychologist or other mental health professional, worries about illnes should subside.

It sounds like you: have gotten stuck in health worries. Have you adequately grieved your mother's death? If no, consider working with a spiritual advisor or a therapist to work through this more. If you believe you have already been able to grieve & deal with her death - then consider cognitive behavioral therapy - to counter your irrational fears. Take care.