Intro and DVLA taking forever and a day to process HGV provisional licence

First of all, I would like give out a huge hello to all members of this community. 

I am currently working in a large depot of a major well known blue-chip transport firm (you know the one with the yellow trucks) doing a range of duties, including yard maintenance, forklift driving, steam-cleaning tractor units for MOTs and looking after chemical delivery hoses, as well as minor fitting duties (such as headlamp bulbs and retorquing wheel nuts).

However, due to the loss of several major contracts in the last year or so, there have been times where there is very little work to do, so therefore I thought about applying for a Class 2 HGV provisional licence and then maybe move on. 

Here is the story so far:

First of all, I attended an appointment to see a doctor who specialises in carrying out HGV medicals by filling in a D4 form, which, along with a D2 licence application form is then sent back to the DVLA in Swansea. Passed the medical with flying colours and the doctor was very confident that I would get my licence back within a few weeks.

So the following day (Saturday 17th March), I sent all my forms, along with my licence to Swansea. But, just under a fortnight later, I got a letter back from the DVLA saying that they needed more info from my GP and a consulant due to my ASD diagnosis.

After five weeks have passed, along with several phone calls, the DVLA sent me another letter saying that they have all the info they needed for one of their many money-burning doctors to scratch their heads on deciding on my licence. 

However (since the last week of April up to the time that I'm writing this post), they are still waiting for a decision on what to do. I have been ringing them once a week for an update (they keep saying that I'm on a "priority" list), but there has been no progress since the end of April.

Is it because the DVLA don't want autistic people driving 18 or 24 tonne trucks on the Queen's highway (I know you have to meet higher medical standards for this catergory of licence)?

I'm starting to get really frustrated about this, and if possible I would like some advice on cracking the whip even more on them.

Sorry about the gripe on my first post on this forum. but I thought I might as well get this off my chest.

Thank you.