I have lychin planus in my mouth, i've had it for the last 12 months i'm on steroid mouth wash but it won't go, can this affect my taste buds?

Yes : Sometimes a course of oral steroids can be helpful and sometimes actually injecting steroid into the area can be helpful. Have you seen an ENT doctor yet? If not, it would be useful to make an appointment for an evaluation.

Taste: Yes it can. See your md to see if there is another wash you can use or perhaps a different treatment.

Cream: Steroid cream you apply directly on the lesions seems to work best. Good luck!

Lichen Planus: I am not sure what type of doctors you have seen, nor how closely they are monitoring this for you. I know if i were the patient, i would see an oral pathologist. They are few and far between, but they might be able to give you further help with this issue as that is within their area of specialty and deal with these types of issues on a regular basis. It might be worth the trip.