I hear ya brother. That's the thing about the internet. Nobody can see your facial expressions etc., so dryer humor doesn't work as well because they can't see that little smirk you're doing will saying something. Sarcasm doesn't work as well either. And I can't even stick my tongue out at anyone!
Sorry about the degree. I'm sure you'll get there, just hang with it. At least you have your associates. Maybe for your doctoral thesis you can look into guys like Bill Murray and Robin Williams. You know, "laugh out loud" kind of guys. Maybe get really wild and check out Richard Pryor. Your professor will call these guys "less dry."
As for jokes going over your head sometimes, in public forums such as this, I use a lot of movie lines or lines from classic sit-coms. But, if you haven't seen them, you won't get it. A couple younger people were laughing hysterically recently about some things they were saying and I didn't get any of it... and thus wasn't laughing. It was from "The Office" which I have never watched and obviously they all do. I haven't been golfing in years, but when people in our business used to hold huge golf outings, I did often. In those circumstances, and many others in life, Caddyshack is your friend. Committing that movie almost completely to memory will take you far in life. That, Animal House, Stripes, Meatballs, Fletch, Fletch Lives, and just a few others, are all you really need to be funny in any circumstances. If people don't laugh at that, their funny bone is broken or perhaps they have indeed fallen for the banana in the tailpipe.
So yes, keep your day job for now, but don't give up hope that someday you too can be an internet comedian.