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.
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.