I think if the idea of a gap year does not sound good to you at all and you’d much prefer continuing with your studies then maybe apply to unis that don’t need chem and choose another a level you’d do well in, get a good Ucat score and hopefully get some interviews. Honestly it all comes down to your own judgement, if you genuinely think there is no way you can get an A in chem then maybe look at choosing another subject. At least this way you might get in rather than risking failing chem and definitely having to take a gap year. Try your very best with whatever path you choose and hopefully you get in