Thanks for choosing "Ask The Doctor" for posting your query.
The colour of vomit that you are mentioning and the colour of stools that you are mentioning suggests that there could be an internal bleed. This might have caused coffee coloured vomiting and black colored stools. Further the light hotheadedness is due to blood loss and hypotension. It would be wise to get a blood hemoglobin done and an endoscopy done. Do meet your doctor and get these tests done.
Hope I am able to answer your concerns.
If you have any further query, I would be glad to help you in future.
Wish you good health!
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.