smoke less / stop smoking
lower strength THC
increased CBD to THC ratio
avoid other things that add to anxiety/paranoia if you take them - meth, caffeine etc.
antipsychotics may help yes, IMHO it's not worth having to take another drug just so you can cope with cannabis though, better to try to fix the cannabis issue itself, if that means you have to stop using it because your body can't cope then chalk it up to life and move on, it's not worth risking your mental health to get stoned!
There are other options for sleep that you could consider as well.