Should I do the IB?

Now I know GCSEs aren't a good indicator of how well I will do, but I am predicted 2A*s, 7As, and 1B. I could get higher than that, could get lower. Who knows.

For Uni's like UCL, LSE, to do the course I would like, I need about 38/39 on my diploma. I am not asking for 40+, but very high 30's. I am aware of the hard work and dedication needed, but for (roughly) someone of my scores on GCSE, am I going to find it near impossible to get that high?

For GCSEs, I know I could've got mainly A*s if I had taken it all seriously from day 1, but I lazed off, and it was too late by the time I cracked down to work.

I do want to do the IB, but it scares me when I read how meeting that type of offer is ridiculously hard, and I am lowering my chances of getting into a top Uni. I would like to hear a good opinion from an IB student (I feel A-Level students are very bias about this topic lol)

Thanks in advance!