1981 volvo 240

halfway to our destination on a 6 hour road trip, we noticed an intense fuel odor. So we stopped and I peered about, finding that gas fumes were emitting heavily from the charcoal canister, said "hmm.. i'll keep an eye on that" about 35 minutes later it continued to smell, so much a slight head buzz kicked in, so we stopped again. This time it was RAW gasoline that was dripping from the bottom of the charcoal canister. We were several hours out still, and worried about this stuff igniting so we looked around for a garage, but of course we chose to drive on Sunday to avoid traffic, so no garages were open at the time. Crossed my fingers, hoped for the best and maintained 55 mph until I made it to my destination. Woke up monday and took it to a local mechanic. Apparently the vacuum line entering into the back of the TB was loose, so they repaired it, charged us and sent us on the way. We had to leave monday to make the 6 hour ride again, so trusting that they repaired everything we hopped on the road home.

Again..halfway home we smell fuel. Pull over and what do you know the damn thing is dripping again all over the ground. (approx. 45-50 drips per min)
So I untwisted the gas cap to help relieve some of the pressure that I supposed to be causing this, and again did the 55-60 mph all the way home.
I pulled over several times to keep an eye on the drips, but it appears to not drip when the gas cap is loose relieving the pressure.

so I really want to find the cause of this, because I know raw gas shouldn't be in the canister, its just fumes (unless I'm mistaken)
is the canister bad? may not be the cause of this issue but now that it's probably full of raw rather than fumigated gas..?
Potentially some hose issues..but why would raw gas be making it into that part of the system?
Fuel line clogged somewhere?
or should i buy a vented gas cap and call it a day? is that a half ass band-aid fix?
my significant other drives the brick to the city and back, and the last thing I want is her in a car that could potentially go up in flames at any time.

Any help is appreciated and I hope I gave enough detail, if not I'll be close to the comp today cause this is my main objective.

thanks,
Cody