Ok well in that case definitely go easy with the squats, yes. If you feel any sharp pain during the ROM, distinct from muscle fatigue / soreness, you should stop the movement. Use your judgment, squatting is a great overall exercise but take it easy as you have been and if pain continues to be an issue you may want to investigate other exercise options, e.g. a hack squat machine.
If you are genuinely "dreading" the workouts, then yeah you should probably stop doing Starting Strength. Enthusiasm for a program is important, regardless of the program. I'm the kind of person who just cares about the results and as long as they're coming I don't ever get bored, but not everyone is like that, obviously.
As for your question about a strength base before focusing on hypertrophy / bodybuilding, the traditional Rippetoe answer has been 200/300/400/500. Those are 1RM in Press, Bench, Squat, Deadlift. More recently he revised it to 175/275/400/500. Those numbers may seem high. The truth is there is no right answer to your question -- everyone is different in terms of their potential for strength, and people have different goals. There is no magic number where if you bench press it, suddenly the door to hypertrophy is unlocked and you can move to higher reps. The reason novices are told to focus on strength in the 5 rep range is because it drives adaptation in mass and strength about equally and therefore allows for optimal progression in both.
In other words, a bench of 175x5 is a fine benchmark. But if you could get it to 185x5 in just two more weeks of training, that would be better. And if you could get it to 205x5 in another month after that, that would be best. Not just because you'll be stronger, but because the process of getting there will itself build muscle, probably at the fastest possible rate (if you're eating properly).
Anyway, your issue isn't so much lack of progress as it is boredom and just general distaste for the program, given that you've been doing it for a while. So you should switch it up. How many days / week do you want to lift? The problem with Push/Pull/Legs, if it's done 3x / week (e.g. MWF), is that the frequency is low. You'd be going from squatting and upper body pressing 3x / week to once a week. If you did it 6 days -- Push/Pull/Legs/Push/Pull/Legs/OFF/Repeat -- the frequency is better, but I'm not sure you want to spend that much time in the gym, and it's a lot to recover from.
If you want to keep lifting 3 days / week, I think an upper/lower or full-body routine would be better. Here are a few good options, though there are a lot of good programs on this site and all over the internet. The Layne Norton PHAT recommended above is good too, but I believe it's 5 days / week.