You're getting anxiety -> panic attack, it sounds like.
A lot of people report that they get anxiety and panic attacks when smoking, even after smoking for years - most common pattern is escalating use as tolerance increases, and eventually they start getting panic attacks (or sometimes they dont, and just decide to take a tolerance break), and then they take a break to bring tolerance down - and then discover that any amount of weed causes panic attacks. There's no consistent way to reverse that, either :-( You're not alone, though.
Be careful with JWH's - some people find that mild blends are fine and don't produce anxiety like the real thing, while others have had them trigger the "anxiety + panic attack when smoking weed" syndrome, thus ruining weed for them.
There isn't a good solution unfortunately. Some report that long breaks can help, others, not so much. Some report that smoking tiny amounts and working up can help, others not. Some find that if they only smoke while drunk, they are fine (and that this helps them get back into it).
Do not start taking benzos to enable you to smoke without anxiety, as they are far too physically addictive for that purpose.
Also, the strain matters alot. I used to get anxiety off of shitty weed, while crazy balls-to-the-wall sativas were fine for me.
Oh, and wtf@nutmeg. Nothing good comes from eating nutmeg - though this does seem to support the theory that it acts as a cannabinoid (in addition to causing all manner of sideffects)