If it’s what you really what to do then stick at it and learn from your mistakes.
I to was in a similar position 12 years ago …
Got made redundant had spent all my life working in factories so decided HGV’s is the way forward.
First port of call was a local general haulage who was looking for trainee drivers, so went for an assessment drive which cost me £30 
well the driver trainer took an instant dislike to me, anyway after the assessment drive he turned and said “forget it son you’ll never make a lorry driver”. I was gutted.
So I thought oh well I will concentrate on passing my CPC in national road haulage, whilst on the the course I got chatting to a TM for a large logistics firm who told me they had just started a their own driver school up and if I was interested 
. I passed my class 2 on the second test because they run a class 1 only fleet it was straight on to class 1 training. This wasn’t has easy failed the first 2 tests badly and then was told the third would be the last attempt. So on this test rather then getting worried that the examiner was in the cab I listened to his instructions and drove as if he wasn’t there and it worked passed (2 minors) .
So after passing my class 1 the first 6 years were up and down trying to find a good company to work for.
For the last 6 years been driving class 2 gas tanker for a good company that respect’s their drivers and for the last couple of years become a driver/mentor.
So stick at it or you may never know where it will lead you.
Ohhh the CPC in national road haulage never used or needed it! however has a newbie to the industry it did me an insight into the legal requirements of both the operator and the driver, this was before the dcpc came in.
Hope this helps you in choosing what to do next.