I’m really good at singles and 1 reps. I can do 5 singles with 30 second rests @ 90% but can barely do 5 reps @ 70% in one set.
Where should I start, to fix this. I’m thinking maybe I need to take a bodybuilder approach work on my hypertrophy, isolation. Etc
That means your work capacity sucks. That’s an easy fix, ditch the singles and do all your sets with higher reps. Progressively reduce rest periods. Also, do some kind of conditioning: prowler pushes or sled drags once or twice a week are ideal, otherwise some kind of sprints work well too.
Now, when you say you can’t squat because of soreness: is it actually painful like an injury (stabbing, throbbing, tearing pain) or just uncomfortable (pumped, burning in the muscle)? If it’s just uncomfortable, suck it up. You’ll get used to it and it’ll probably get better after a set or two anyway. If it’s actual pain, there’s something wrong you need to address.
Yeah, it sounds like your conditioning is terrible. If you struggle to do five reps at 70%, you are really really out of shape. That’s also contributing to you getting really sore. Being out of shape makes it take longer for you to recover and can cause more soreness. Do conditioning and maybe 5 minutes of mobility a day and it should take care of itself.