Lying down get ll back pain, & tachycardia + high bp. Have lhs L5 spondylolysthesis & si joint arthritis. Pt, pain meds, accu, chiro only temp help.?

Spondylolisthesis. This may suggest that your spondylolisthesis is unstable and "slipping" when you lie down. Often the measures that you describe provide only temporary relief. Injections may help but can aldo be temporary. Essentially the spondylolisthesis is a mechanical problem that may ultimately need to be fixed.
Arthritis. Many times BP and heart rate can go up when you are in pain. Mechanical lbp frequently increases in certain positions and with certain activity. Most lbp like this, especially without leg involvement, come from the degenerative joints of the lumbar spine, leading to the spondylolisthesis. Injections of these inflamed joints may help a ton.