Have inappropriate sinus tachy and now severe htn, crp very high, hr is 120-154. new state, seek out cardiology ?

Tachycardia: Heart rates over 120 would not be simple sinus tachycardia and do require cardiology evaluation and treatment. Heart rates consistently over 90 at rest are abnormal and require evaluation to find a cause( hyperthyroidism, fever, medications, etc).

IST: Yes visit cardiologist please. Ist could potentially weaken heart. B blockers good for condition. Need to rule out other conditions such as thyroid but can also be associated with pots especially if symptomatic.

Need further test: From your question it appears you had already a work up for your tachycardia, as you define it as inappropriate sinus. However, tachycardia, HTN can potentially involve other disease mainly related to inappropriate release of hormones. Blood test could help in this metter and a primary care physician could be helpful in assessing the overall condition. As cardiology, I would look for EP specialist.

Yes: Yes, you should definitely see a cardiologist to get yourself evaluated. A simple hotter monitor and echocardiogram will be able to tell us a lot.