My last comment is also consistent with Mark's observation that sleeping in a bad position causes blood flow and nerve issues.

Specifically, sleeping with the head tipped forward could be compressing the vagus, accessory, and glossopharyngeal nerves as well as the internal jugular vein, leading an exacerbation of symptoms.

I too cannot sleep with my head tipped forward. My attempts to sleep in a "normal" position have never ended well.