I don’t know because I’m not a big biologist/chemist (I’m a bit curious as to your third A-Level/qualification,) but I do know that biochem is indeed hard to get into (according to my bio friends!)
I’m not gonna tell you what to do, but I have suggestions as a first year student changing degree and having friends who aren’t, and love their degree.
Don’t be overwhelmed, there’s a TLDR at the bottom, I know I can talk for ages.
Degree:
Regarding course content, if you’ve not done so already, I would highly suggest looking up degrees and seeing their ‘modules’ or ‘units.’ They sometimes have descriptions of what you’ll learn in them. If you are already not interested just by reading those alone, then there’s a chance that degree is not for you. I am changing degree because I focused so much on my career and the direct path and entry requirements that I kind of ignored what the uni told me I was going to learn, so ignored vital info!
It seems you have a diverse range of interests, and it’s hard to explore them all in your time, but I would suggest dedicating small bits of your day (as small as 5 mins, maybe as much as 30), exploring all of them daily or every 2-3 days.
To try and narrow down the options, I would suggest looking at already previous academic experience/interests/pursuits that you have, and I’m not just talking about the A-Levels. What have you already done academically that’s interested you? Is there anything that you commonly watch/are interested in/read about that you don’t force yourself into watching but can’t help but find yourself in, not orientated towards a degree or career but just in the pure love of bio and chem? (Or pharmacy or opt…) Don’t try and plaster things into your personal statement to seem suited to a degree, but do the academic things that ACTUALLY interest you (rather than the things you may rush to do before the October/January deadline!)
Career:
Regarding career, have you gone to any talks with people in those professions too? Not just career based but topics based! (I think UCL does talks, a lot of unis do talks, open and free, maybe search for public talks, or refine the search to ‘for sixth formers’ or ‘year 13’s’ or ‘17-25’ you get the gist…) Or could you possibly go online and look for these people (I’ve found that people on YouTube compare similar careers or even list careers after ‘x’ degree.) Any work experience or volunteering you’ve done, or are interested to get into in year 13? (it flies by! Try searching now as we get to the end of the holidays or when the academic year starts.) And Summer or learning days/weekends at unis!
Regarding not finding places in your city, it is really tough! So far I’m gaging that you wish to stay near home, and that might be the case after graduation, but it might not be. Have you looked at the availability of jobs outside your city? Does it seem more promising?
Do know that considering you’re in STEM, it’s highly unlikely you’ll just do your bachelors/undergrad and then go straight to the job market, it will probably be a few years. Chances are maybe the job market in your area would’ve changed, or you may have enough experience to even change it yourself!
TLDR:
Biochemistry is hard lol but it’s possible! Look at Course content yourself on those degrees you stumble upon. Dedicate time to this, not just wish for the time (early morning good to check, or evening?) Look at things you naturally waffle happily about for ages regarding bio or chem, (or pharm.. or whatever floats your boat regarding bio or chem..) even ask people around you what you waffle about most!
For career, try and find talks on not just job but topics, Unis do these for free for the general public and aimed toward sixth formers too! And if push comes to shove, youtube also does this, with some people comparing similar careers. There’s work experience and volunteering which is hard to acquire, and learning days at some unis which are also hard, but they’re still possible. In terms of jobs in your area, you may unfortunately have to move, or there’s a chance that because you’ll spend so long at uni as a STEM person, the job market will have changed, so don’t worry too much.