From currently accepted knowledge there's nothing supporting that olanzapine should have permanent effects or stay in you body for such a long time but om the other hand we have a lot of people here reporting similar issues, mostly with depot shots but also with pills. My personal impression is that antipsychotics are nasty and given much too readily - I tried most of the newer ones, including these fancy partial agonists, but all they did was clouding my mind and make me unable to enjoy music. Went away after substance washed out though.
For how long, and how much olanzapine were you taking? What drugs don't make you trip like before?
Weird thing is that antidepressants interfere more with tripping than (lower doses of) antipsychotics probably but I'm not sure, just that while on SSRI any amount of shrooms would be next to inactive and this lasts, as well as sexual side effects and discontinuation syndrome - much longer than just the drugs half life but after eight months most stuff should be reversed.
Maybe you could try a more potent psychedelic like one of the lysergamides? In some case this can help recovery too, there's a lot of growth factors released during a trip. 1cP-LSD worked for me while on venlafaxine like it should without.
