Op, just want to re iterate what others have said, you are an amazing mum and your DS's attitude and effort will take him a long, long way.
We live in an area with no grammars near and ours is a 'one comp' town, which is where my 2 went. DS was second set for most things, but he is a worker. Got the college award for effort in year 9, amazing given each college has 2 forms in each of 5 years, so he beat approx 300 others to the award.
Good but not stellar GCSEs, but at 6th form, where they are more independent, he beat many who did much better than him at GCSE. He was ill doing AS exams, so bombed one of the exams in his chosen uni subject, but with a lot of effort and a resit in that exam, pulled a D up to an A at end of 6th form. He is about to start his second year at a good uni, doing that subject - a pure science - with a high first in first year.
He had a retail job in sixth form and went to back to same shop in uni city at Easter. He has just had to resign as the set shifts were much longer in uni city and not conducive with 2nd yr of a science degree. At his leaving interview and on leaving day he was told more than once that if the supervisor/line manager could offer him shorter shifts then they would, as he was such a hard worker.
I have a friend whose 2DD went to grammar and DS equalled and beat their A level grades, and in more academic subjects.
Have another friend who is obsessed with grammar schools. She sat at my table as her eldest was starting yr 11, and said "Anything less than all A at GCSE is a failure". DS was sat next to her, having just got his results and with only 1 A to his name ☹️. I will be interested to see how her kids' lives and my son's pan out.
DS gets his work ethic from DH, who, despite failing his 11+, has done very well for himself, going to grammar for A levels, doing a HND (could have done extra year for degree but wanted to start work) then working very hard, often working long hours, doing long commutes. He has as good a life as his sister who passed 11+ and went on to do medicine!!
My DB on the other hand, passed 11+, v good O levels, did 2yrs office work at 16 and hasn't worked for the last 39 yrs! A good education wasted on someone with no will to work.
Your DS will go far!!