Need some help re: sativa

Hello all! I'm new here...

I come to you all for advice and wisdom. I have been growing a mystery strain of weed that appears to be some extreme sativa, for a 3rd year. It looks like a sativa, in it's sheer size and shape (it's about 6 feet tall now) and it takes for EVER to finish flowering. I don't really like it but for some reason I have tons of seeds for it.

Anyway, I believe this plant was germinated in Jan 2010, started indoors and put outside for the whole summer and is still going for heavens sake. My big problem is that the trichomes absolutely refuse to change colour. I did a partial harvest 5 weeks ago, and the buds take forever to cure, the high is 'two tokes and you feel it in the back of your eyes' (zero body high) and no matter how much you smoke after, you'll only start getting a headache and want to cough. It's a great social high, but thats NOT what I'm going for. I want to smoke this before bed and sleep well, not stay up all night a little hungry, energetic and annoyed. That's after 3 weeks of dry/cure. Now at 5 weeks, it's starting to blur vision a little bit, but still no real body high. I must mention the plant is still going now, because i'm tring to get a real narcotic high out of htis plant. yeild is high and buds are very, very resinous - albeit very fluffy and full of sticks. it started out smelling like passion fruit with some lemon early on but now it reaks of cat piss. the leaves began to yellow out over a month ago, but trichs refuse to change colour!!! even some evidence of the branches are just dying out and molding on the plant (minor, but it's obvious shes way, way too old)! Can someone tell me what is going on? This strain has always irritated me like that. It's been on flush for at least 4 weeks. Has anyone heard of a strain that will not change trich colours??? I really dont know what to do. thanks!!