Hey, welcome to the world of weed I suppose. We have a MEGA thread
here about anxiety and paranoia from smoking. When you are paranoid/anxious from pot, it's not necessarily "psychosis" and afaik, ability and lexapro have very little to do with a cannabis high. What do you mean by you hallucinate when you smoke? Do you actually see things that are not there? Weed usually causes more physical distortions of things if it happens as all, unless there is delirium you aren't actually hallucinating.
If Sour D didn't make you paranoid or anxious, maybe it's a strain you should stick through, if you click on the CD Directory link in my signature, there's a strain thread in there, and different things in each strain can either increase or decrease various side effects.
Feel free to look at the first thread I linked you to on how to handle paranoia/anxiety during a cannabis high, but we generally don't allow self-serving threads like yours would be considered, so I'm going to close this...after reading through that thread and looking around in CD a bit more (a wealth of information if you are new to cannabis and cannabis culture), feel free to PM me if you have any questions.