I wouldn't apply without having done some veterinary work.
It is a really stressful and underpaid profession and unfortunately we have a terrible retention rate which means people are undergoing all the training to become vets and then deciding the career isn't for them. Additionally, the veterinary profession is one of the top careers in terms of suicide rate. I cannot stress to you enough how important it is to properly research this profession before you try to get into it, therefore you absolutely should do some work experience in a vet practice. Yes it is hard to get, but every other applicant to the course has done it.
Veterinary surgeons do like animals. But if you want to be a vet because you like animals, this probably isn't enough to keep you happy during the career. Pets don't bring themselves in, and you will need to work with their owners (who often do not trust you) to try to provide the best outcome for the animal that you can. Owners can often be aggressive, upset and overall make your job difficult when all you want to do is the best for their animal.
You do need to
really want it in order to succeed. Vet school is highly competitive, with 11+ applicants per place for some courses. It doesn't yet sound like you are sure you want to be a vet, so it is probably best you figure this out so that you are better able to convince the admissions team that you should be chosen for vet school. The interview process is intensive and difficult and you need to be so clear that you know all about veterinary medicine and why you are a good fit for the profession. If you are still deciding between different degrees, then you probably don't yet have the determination to succeed during this process... yet!
The MOOC was released during covid, so while it is still accepted, you would not be a very competitive applicant without having done real work experience.
Also, what you refer to are not just 'STEM' degrees, but university courses which lead you straight into a career. In this case, pharmacist and veterinary surgeon. These aren't really courses you study because you're interested, but you should study because you actually want to be a pharmacist or a vet. They are vastly different careers so I recommend you figure out which one you'd actually like to be.
Additionally, why is two gap years not an option? I did two gap years while I did my veterinary work experience, and it worked out fine and I'm really happy with the route I took.
My advice: do some work experience in a vet clinic (you will have to have this in order to apply anyway). If you like it, then you can see about applying to vet school later this year.
Us here at TSR will all be happy to help you construct letters to clinics, writing personal statements etc. But I do really think you need to decide if you want to commit to veterinary first.
Good luck on your journey.
P.S. Don't rush into applying for uni. Even doing just one gap year you will graduate later than your peers anyway. There is no rush! Just make sure you choose the right course for you!