Hello firstly ill start with some info about myself, I'm 22 male, eat healthy, workout now and then not overwieght but starting to try and tone up.

Now onto the problem.

Ive been having a lot of pain in my lower back/ left buttock it hurts a lot more when lying down it comes and go's and haven't noticed a patern of any sorts ( i.e. it does it if I've been lifting wieghts or if I haven't n some times doesn't hurt atall ). The pain gets so severe I can't move, the most intense experience I've had is waking up in the night after trying to roll on my side in my sleep the pain was so severe I couldn't move anything not even my arms to call for help but eventually I managed to get up and it eased up. Sometimes it hurts to walk but I've also noticed it hurts to the beat of my pulse.

After seeing a doctor I was referred to physio that I'm still waiting for after 3months, anybody think what it is?

Maybe see a well-respected chiropractor? Could be sciatica or a disc problem or who knows what. Did the doctor take x-rays or do an MRI?

nope no x-rays or mri. And I saw a chiropracror when it first started and didn't help.

I've had pain for 35+ years, not so much in my lower back but in places in my lower abdomen and legs. It is from spinal nerves, however, because the lowest nerves (sacral, which actually come off the lumbar nerves just above them) wrap around to the front. I suspect that you have either a taut muscle from the way you life weights, or a pinched lumbar nerve or a problem with a lumbar vertebral disc. You may not warm up properly! Or it may just be the configuration of your body, since none of us is exactly like another.
The first thing you need is heat. Heating pad and hot baths, soaking as long as you can. Gently but frequent exercise, more in the yoga or tai chi category. Massage if you can get it.
If it persists another month, get an MRI. They are expensive. I had a CAT scan and an MRI over all the years, and neither showed anything.
I went to a GOOD chiropractor (tried a closer one too, who was terrible) who did help a lot.
But a lot of the work is yours. Talk to a trainer or a sports medicine clinic. Stop lifting weights, except maybe bench presses.