I was in a rush and didn’t measure original gravity unfortunately. I guess I could do that today although it’s been fermenting about two days. Didn’t add any nutrients either, just a handful of raisins. Last time I used fermaid k for some wine it left a nasty taste. Was aiming for around 12% alcohol or somewhere close to that. Using champagne yeast.A three gallon batch of mead might have six to 7.5 pounds of honey and water added to make the target volume. You aren’t too bad at five pounds. On my part if I made the batch fit the target carboy I would stay where it fit rather than having a 3.69 gallon volume.
Our normal starting point is based on the gravity. Yeast will stop fermenting/ die if the osmophilic potential is too high (concentration of sugar). Yeast like below 1.100 specific gravity. Have you measured gravity? There is some variation in moisture content in honey so you don’t know where you are unless you measure.
What finished alcohol do you want? Normal for a high alcohol is to step feed. Yeast need some extra oxygen and nitrogen along with sugars to produce high ABV.