It seems to me a print that comes up fully in two seconds is probably overexposed. I spent years and years in a dip-and-dunk darkroom and this has been my experience. You said "after two hours" but did not say how many prints in that time. Have you tried a new batch of developer after a while, or refreshing your developer? Test strips are a great idea. I'm trying to make 11/14 prints on an inkjet printer and I sure wish I could make test prints. It would save me a fortune in ink and paper. By the way, I just bought an enlarger for 35mm and 120 film and hope to be slogging away soon up to ny neck in "soup" and fixer.
ha, well I pretty much calibrate wide format inkjet printers for press proofing for a living...I get to play with $10,000 RIPS though since I work for a large packaging printer.