Brief Answer:
Evaluation

Detailed Answer:
I understand what you are saying.

This requires thorough assessment. When I see someone like you in my practice I order the following tests in addition to a comprehensive physical examination:

CBC
CMP
TSH
FreeT4
Plasma free metanephrines

As you have stated that your recent bloodwork mostly came back normal except for low vitamin D, it is likely you have already had some of the tests I have mentioned above.

The low vitamin D has not been shown to be directly associated with such blood pressure fluctuations but nonetheless should be treated to target normal levels, with a plan to keep them in the normal range for life.

The other tests I have listed above are for thyroid function. Abnormal thyroid state can cause blood pressure changes.

The last test (plasma free metanephrines) is to screen for a rare condition called Pheochromocytoma in which spells of headache/sweating and chest pain/Blood pressure swings occur. Although you clearly dont seem to have such episodes but. It would be well worthwhile ruling out this condition.

The unintentional weight loss also deserves a systematic check up. The 'CMP' blood test includes a host of items which give a fair idea of many laboratory parameters that need to be checked in the work-up for weight loss, such as
Glucose
Calcium
Electrolytes
Kidney function tests
Liver function tests

So if these are normal too then you should see your family physician to consider further evaluation for this.

---