Sounds like you got drugged with some spiked rum or possibly someone slipped a "mickey" in your drink, and perhaps the exposure to the old man was the intended outcome. When you are age 50 or age 70 and you are a pedophile it really doesn't matter much if the victim is 16 or 19 or 21, as they seem all about the same to an older guy that age. Your experience here illustrates a good reason for young people to avoid heavy drug and alcohol abuse, especially around suspicious people. Yes, what happened to you was abuse. The way that I see it you were taken advantage of without your consent, even though you were a young adult at the time. Many young adults have been taken advantage of without their consent over time while under the influence of drugs and alcohol by those with ulterior motives, often by someone that they had previously trusted.
Hope that talking about what happened helps you feel a little bit less burdened. You have my support.
"We stay here, we die here. We've got to keep moving". Trucker Mark