But are you willing to risk injury to move those heavy weights? I'm willing to bet you are young. I started that way too. Always tried to increase strength, not muscle shape and health. Luckily I never got any bad injuries or tore anything, only minor temporary misshaps. Now I don't even use whey protein and doing better by learning what to eat for what works with my body. Before I wasn't really listening or thinking. Just doing it all out. Not good.
It sounds to me, as if you're equating strength, solely with heavy one-rep maximums. That's not the only way to increase strength.
If you bench 300 for 6 reps and 8 weeks later, you can bench 300 for 10 reps or 315 for six reps (or better still, 315 for 10 reps), you've become stronger.
The way you prevent injury is by warming up properly, eating plenty of good food, and gauging your body (lifting heavy when the joints and tendons are up to it, while scaling back in poundage when they're not). Every workout doesn't have to and shouldn't be and "all-out" one. That's how people get injured, thinking they have to torture themselves each session or they won't grow. As two famous bodybuilders put it:
"Train; don't strain" - Bill Pearl, 4-time NABBA Mr. Universe (and professional strongman, I might add).
"Stimulate; don't annihilate" - Lee Haney, NPC National champion, IFBB Mr. Universe, 8-time Mr. Olympia.