A level admission issue

Hi,
I’m in a tough spot right now; I didn’t get the grades needed for any Sixth Form colleges and have been rejected from multiple colleges for the course I want to study. Many have suggested considering BTECs or T Levels, but from what I know, you need A Levels to study computer science. I’ve heard about online A Level courses but I’m not sure what they are or if they’re worth enrolling in. Do universities even consider them?

but from what I know, you need A Levels to study computer science
Not true. Some unis accept BTECs and T Levels, but you would have to search for them.
I’ve heard about online A Level courses but I’m not sure what they are or if they’re worth enrolling in.
They're "worth" doing (I hate that term when it comes to courses). Your exams and assignments are marked by third party invigilators approved by the exam board that you study under, so they're the same qualifications as you would have gotten as if you went to a normal college.
The problem is that the tutor support is limited, so you don't get the classroom experience as you would with offline colleges. This makes the learning a lot more difficult unless you are particularly used to the online learning environment.
The other problem is that you often need to pay for the course and pay to do your own exams and assignments - you need to attend approved exam centres for this.
Personally, I recommend you to resit your GCSEs and reapply for A Levels before you're 17. This is probably the cheaper option, since you do your exams for free and you would have full tutor support.
A Levels still remain more widely accepted than BTECs and T Levels for most professional qualifications and degrees in any subject from any uni (local or abroad).
If you need to find places to resit your GCSEs, let me know the name of your town and the subjects you need to resit, and I will try to look for colleges in your local area.
Resitting Maths and English Language should be free. For other subjects, you might not be as lucky since not that many adult colleges would offer them as GCSEs.
Failing the above, there are online GCSE courses that you can do, and you can resit the exams at an approved exam centre.
Should you do resit, I would only resit the GCSEs you need as opposed to redoing the whole thing. This isn't about your ego as much as about making you eligible to study the A Levels that you want to study.

The problem is that m going to be 17 soon, the subject I would want to retake would be maths but I got a grade 5 in it which is the highest you can get in foundation so the exam won't come under resit but instead it would be considered as writing a new exam. I am considering writing higher maths but I'm not sure when I should take the exam.
Yes, I would appreciate it if you could share me places, I could resit/freshly take my GCSEs privately as it's clear that the school won't support me. I live in East England. I have lots more questions to clarify which m not getting any help and I'm not sure where to ask.
Thanks for the advice though! really appreciate it.