I would ask my doctor, It may be your pulse is to high,But it seems to me your heart is racing. Just food for though.
You should not attempt to raise your blood pressure without consultation with a physician. There may be several factors involved in your abnormally low blood pressure. Your heart is compensating by speeding up. Clearly, you could lose some weight. That will help. Keeping well-hydrated is another fairly simple thing with no contraindications. Other than these two suggestions self-treatment could result in a life-threatening emergency.