Vertigo at night in bed

I have had severe vertigo while lying in bed at night for quite some time. It is not every night--sometimes I won't have this for almost a year. But suddenly it just comes on. When I get up to sit on side of the bed, the room is spinning out of control. After these spells, I feel headachy in the daytime (no dizziness) and am uneasy that something is drastically wrong. My doctor years ago just dismissed this and I think there is more to this. Some of the posts seem to fit into what I have too.