hiya kitty girl you do NOT need A-level physics to do medicine, so worry not about that
To be a teacher would take you between 3-4 years of undergraduate training leading to a modest salary.
You would have office hours and fantastic holidays of course they would be confined to out of term time for the most part. You would never be rich being a teacher (unless you pursued an outside business venture) however friends of mine find the job very rewarding although at times stressfull.
Medicine on the other hand....
Please don't allow this next paragraph to put you off, if you are passionate about something you should do it.
1) Get into med school, hard...
2) Train for 5-6 years as an undergraduate, harder...
Hard part over?...Think again?
Lets assume you found med school a doddle and passed (odds are in your favour once you get past first year, statistically speaking)
3) Work (assuming you get a job first time round and its not guranteed anymore) for 2 years as an FY1/FY2 (used to be known as House officer and senior house officer years)
The pay isn't bad (but you won't be buying a porsche at this stage) but you'll work long hours under difficult circumstances (and this is the beginning of your training)
4) Well you said surgeon didn't you..so you'd have to get onto the surgical ST (specialist training) programme..hard..because its a popular choice and of course only a fininte number of training places/posts in any given area, you'd certainly have to be willing to move around the country.
5) Now train for approximately 5-7 years to consultant level.
During this time you would be working long hours but your pay would steadily increase (you can't really do any private work until you are a consultant and once you are/if you'll be contracted to a high proportion of your work in the NHS) but you would by this time have a very decent salary and hopefully a job your passionate