hi
sinus tachcardia can be due to multiple reasons,
related to the heart, (valve related or blood vessels)neuropathy, infections,
thyroid variations, stress related, sleep disorders,
electrolyte imbalance,
severe dehydration or drug induced (bronchodilators, decongestants, brain stimulators).
it is better to get evaluated with all these causes.
if the cause is ruled out due to nervous system, you can continue with non-specific betablockers like propanolol, can be continued added with
clonazepam.
multi vitamin especially methylcobalamine supplements can be of some help.
please destress yourself, maitain proper hydration, slow warming up exercises before waking up from bed.
all the best
take care