F53 95 Vectra -- leaning to the passenger side

Neither CHF nor the track bar have any effect on this.

You said your rear suspension is AIR. Is it straight air (like with ride height valves) OR is it the stock Ford F53 leaf spring suspension with SUPPLEMENTAL AIR BAGS?

If the latter, first thing is to deflate the air bags and see if the leaf springs on that side have failed and/or if there is excessive wear in the shackles/spring bushings. The supplemental air bags can assist, but not overcome a failed leaf spring.