Biofeedback is another option. I don't know how much it costs to have some sessions with a practitioner who uses biofeedback, but maybe it would be covered by insurance if you have medication-resistant hypertension.

My hypertension is somewhat controlled (I take one medication), but it is always creeping back up there. It is usually pointless to even measure my BP at the doctor's office, because it shoots way up whenever I go there. It is lower when I monitor it on my own throughout the day. I found that I can get it lower by a few points by doing different things. Each thing might affect it just a point or two, but it adds up. Lowering salt in my diet helped a few points, as did taking flax seed oil, losing a few pounds, exercising, getting treatment for my sleep apnea, etc. I guess apnea can be a definite cause or contributor, so I throw that idea out to you in case you suspect you may have sleep apnea. The main symptoms are daytime sleepiness and snoring.

I looked at that resperate link and am intrigued. Wish it wasn't so expensive.