Firstly that trainer is a @#@$ moron and you should shoot him at the first chance you get, his attitude is shit and he is basically telling you to stop living and wait to die and I am not fine with that attitude.
Secondly you need to figure out why you are getting the pain. Especially at your age there might be a lot of muscular imbalance which needs to be addressed before you can lift weights that heavy
Thirdly you might just be limited to not exceeding that limit which might just be a reality but not as bad as it may sound.
Try and get a video of your form and have that assessed preferably by a professional physio.