In England & Wales although not routinely supplied on the NHS, there is currently a "study" that you could probably enroll on to get Prep (free of charge) from your local (or a near by ) GUM clinic. Alternatively you can buy it online through www.iwantprepnow.co.uk for around £40 a month. I should add that in Scotland the NHS do routinely provide free PreP at GUM clinics virtually on demand.
One further note, pulling out does NOT prevent you catching HIV, it is present in pre-cum and there is always the risk of minor bleeding. So if you want to play "safe" I would recommend condoms or Prep (or both 😄).
Or like a number here, enjoy the risk factor.