I often see people at the gym that are regulars.
They regularly come to the gym.
They regularly do the same routine
They regularly mention (moan) that for all their hard work they aren't seeing the results they expect.
They regularly say they don't need a Personal Trainer :)
They can be given all the good advice in the world, they just aren't ready to listen.
Coming to the gym - great start.
Exercising regularly - fantastic!
Regular routine - well if it's not progressive then once your body is used to it then it has no requirement to adapt.
Moaning? Do something about it. Let me correct that. Do something that will positively change the outcome.
Not wanting to use a Personal Trainer - that's a personal choice,*
There are several reasons that a routine may not be working. But if your routine is progressive/varied and there is no change then the main culprit is usually nutrition (food and drink). Stop and look at how much (and what) you are consuming.
* If you are having syrupy coffees each day, drinking most nights or too excess, dining in on too many take-aways etc. then cutting back on these things could pay for a PT session whilst simultaneously helping you towards your health and fitness goals.
So, are you getting results from your training routine?
Is it the results you want?
If not DO SOMETHING about it.