"Llanelli didn't beat us, it was our own failings that beat us in the end," said Campbell.
"We were robbed, but it was us who inflicted the damage by switching off in the second quarter.
"We had done more than enough in the first 20 minutes to show that we could get a decent result - but then we spoiled things by letting them carve out three tries without really having to work for them."
Campbell added: "We are now out of the running to qualify - but our campaign is not dead.
"Our guys have learned some harsh lessons of the reality of rugby at this level and they must use the next three matches to continue that process.
"Our priority, however, must now be to finish as top Scottish seeds in the Celtic League."
Llanelli director Gareth Jenkins admitted he was hugely relieved to hear the final whistle.
He said: "Glasgow were putting us under real pressure at the end and we were scrambling a bit.
"This is an enormous result for us because Hughenden is always a tough place to earn a result.
"We now have to focus on beating Glasgow again at our place next week and build towards the final two matches against Northampton and Toulouse. At least we have given ourselves a chance."
Hugh Campbell's full comments can be read here.