For some people it takes 1/8oz or so, until they are more experienced and familiar with the effects. Often, once one has become familiar with the effects, lower doses can be used for almost the same level experience.
yeah tolerance can be a bitch... and I can almost gurantee thats why it hardly effected you. Shrooms wernt meant to be takin all the time like u did. But hey... if u want to, go for it. 16 year old girl, only 120 pounds? Wow ure small