To be offended by GP comment?

[Macadamia1976]

I have severely injured my lower back. I'm in agony and can't move without pain.
I bent down, lifted a heavy double buggy up from the ground, twisted round whilst bending over to lift it into the boot of my car then overstretched to position it in properly. I did this really quickly and something snapped in my lower back and I suddenly felt searing agony.
After initial urgent care treatment and being diagnosed with a torn ligament, I had a follow up with GP for pain management.
Never seen him before.
He was in his late 30s, maybe 40.
He said "I fail to see how lifting a buggy into the boot has caused this."
I said "Well I was told in hospital it was a combination of bending and twisting my lower back whilst lifting a heavy object. Plus I have an old injury in the same area of my back so I think maybe it was a weak area..."
He said "No, I think this is wrong. It's not possible to be in as much pain as you say you are in from putting a buggy into your car."
At this point I was confused by why he was challenging my injury. I was in pain, and was there for a pain relief medication review.
He said "It's because you need to lose weight."
I said "Pardon?"
He smiled for a few seconds, then said "Yes, you need to lose a stone from your tummy area, if you don't mind me saying" whilst really smiling. "Then your back pain will resolve. You have done this to yourself by eating too much and the stone in weight that sits on your tummy is putting a strain on your lower back. It wasn't lifting the buggy. I'll give you more painkillers but you need to get rid of that stone of weight on your tummy".
I didn't even realise he had even noticed my tummy.
I was wearing trousers and a top.
I am 5ft 7 and weigh 11 stone.
I wear size 12 to 14 clothes.
I've had 2 emergency c-sections so I admit I do have a tummy overhang, but I hadn't thought of this as a problem, I just see it as a result of having emergency abdominal surgery 2 times to save my 2 DC's lives when they were born. I don't really think about it, I'm too busy looking after my DC and working hard in my job.
I was almost crying in pain during this appointment.
AIBU to be upset by his comments?
Or am I in so much pain that I'm feeling oversensitive.
(Edited typos)

I herniated my disc so badly I got cauda equina from doing.. nothing
And I broke my ankle getting out of bed

Useless GP who complains about weight and offers no constructive advice about how to lose it. Besides you're not overweight anyway OP 🙄.
I would be inclined to get a second opinion on your back. It could be a slipped disc or sciatica, either way you need to know what you're dealing with.

I massively injured my shoulder by putting seatbelt on child in child seat whilst also pushing it into place, so the same twist under pressure and I was fitter than fit but it took ages to heal with sports massages and chiropractor / acupuncture. Chiro explained just how bad that twisting is. useless doctor

When I was slim, I had terrible back problems, I've put on weight and they've improved. Mainly due to a back care maintenance course which eas amazing, despite me knowing most of what they told me. Someone else telling me seemed to make it easier to put into practice. Very poor GP I think, else having a bad day.

Frankly, the average GP has forgotten what the S stands for in NHS. They work hand in hand with the commissioning bodies and have just tied themselves up in red tape that has made work for themselves.