True, many doctors are baalei gaava who don’t believe in Hashem, Tov shebirofim l’gehenom, yet doctors were given permission to heal and we have a chiyuv hishtadlus to use them.
As for alternative medicine, here are 3 psukim to think about:
M’chasheifa lo sichayeh.
Tamim tihyeh im Hashem elokecha.
Ushmartem m’od linafshoseichem.