I went through similar for months - very horrible. Strangely when I rode the bike I never had a problem (thankfully) ........ the reason why appears below.
The GP (I and my Wife both had the same opinion) didn't believe me when I said "I get pain in my gut when I suffer the vertigo"
I had an attack in the middle of the night once, and my Wife called the ambulance. The paramedic said "he looks like a heart attack patient" and wired me up did 4 prints and said " strong heart, but we'll have to take him to hospital" all said as if I wasn't there
Another attack one morning whilst eating breakfast - Wife phoned GP who said "we can't fit you in" so Wife said "you aren't taking this seriously, I'm bringing him anyway". At the GP I was told 'you look ok now' to which I replied "it's something to do with my digestion, once I was sick I improved" They just said 'inner eye - take anti dizzy pills. Then when I refused they said 'don't you want to get better?' and dismissed my desire to find out what was really causing it, not just mask the symptoms.
My Wife (in her wisdom) said "it's clearly digestion, why don't you go to a nutritionist?, which I subsequently did, and her first reaction on hearing the symptoms was "Dozey medics...... I bet a pound to penny it's lactose intolerance -
come off milk straight away"
I've been ok ever since - strangely it doesn't show up in allergy tests.
When I rode the bike I just carried a water bottle and didn't eat anything - no problem!