I was diagnosed pretty quickly as well and at the time, I was not on an antipsychotic to cause symptoms. I was doing repetitive work at the time and to this day, I can not move my hands in those positions or I get pain.

However, I am now on an antipsychotic and the difference I notice between the inability to move, numbness, and/or the tingling between the two is that: the carpal tunnel can be relieved with warm soaks in a warm water baths/soaks in a tub/try/or sink or wrapped with a moist heating pack (can be found at pharmacies), or with pain relief to start out with ( like anti-inflammatories such as motrin/ibuprofen or aleve/naproxen sodium); the symptoms caused by antipsych med cannot be helped except by lowering the dose. Meanwhile, I have learned to find a balance between the dose I can function with and the side effect of the antipsych.

Do more research to see how your symptoms fit. Talk further with your doctor to get his opinion on how to proceed. It could be a process of elimination by trying the soaks/heat packs and anti-imflammatories to see if they help, which will give you a better idea if it is the carpal tunnel; if not helping, you will know it is the antipsych med and can evaluate this further with the doc who prescribes it. OR talk to your doc about decreasing the psych med, to see if the symptoms decrease or are eliminated. Be sure you are in touch with them though if you do this.

I hope you find help soon no matter which category it falls into. Hang in there.

Loxapine Side Effects in Detail - Drugs.com
Carpal tunnel syndrome Definition - Diseases and Conditions - Mayo Clinic