Very late timing in terms of replying, I know, but a few people here do not have their facts right.
a.) You could definitely apply to a graduate program in the UK and get in, and they're amazing schools. I'm currently an american attending the University of Edinburgh who's particularly interested in medicine and has lived with 6 different medics (and dated a few others!). Edinburgh is one of the best medical schools in the world, and the programs they offer at the university are often expensive, but still cheaper than many US options (I chose to come to Edinburgh instead of BU because it was over half the price for the same, if not better Education). It depends on where you apply though. Ireland also has an US/Ireland program, which might be a good link for you?
b.) The UK puts a HUGE emphasis on community service. The majority of their students here don't have any laboratory experience or bachelors degrees, so the fact that you have those as well as community service is a plus.
c.) It's super easy to apply to British Schools. There's just one application, personal statement and reference to fill out and one cheap payment (compared to the $100 per application in the states). The only downside is they limit how many schools you can apply too, so choose wisely if you do!
Don't let other people put you off, British universities outrank a lot of American ones on an international scale, and that includes medicine.
Hope I'm not super late and good luck!