Hello drummerboy. Sorry you're here, but you will get great support from lots of people. We know it's shocking getting a cancer diagnosis, but once you've started the hormone treatment (which you already have with the tablets), it stops the cancer progressing for now, and you have plenty of time to consider your options. This isn't like some other cancers that have to be removed very quickly.
Do you know which LHRH drug you have been prescribed? There are a few different ones, with different injection frequencies. Zoladex/Goserelin is a common one. Injections are normally every 12 weeks, but sometimes the first one is just 4 weeks. I'm on Zoladex. Prostap is another which is usually every 3 months, I believe. The nurse at your GP practice will likely be doing these injections at least once a month to different patients, and GP will know less about administering them than the nurse. The arrangement for getting the injection varies between surgeries. Some keep the stock themselves, some will give you a repeat prescription to collect beforehand and bring with you. Contact the nurse beforehand to find out how it works at yours. If you have online repeat prescriptions, you could login and see if it's been added to that. If you need to get a prescription, it's likely to take at least a day, as the pharmacy is unlikely to stock it.
You will probably be on hormone therapy (HT) for 3-6 months before your radiotherapy (RT), because that makes the RT more effective. Most people stay on HT for some time afterwards, 1-3 years being typical, again because this improves outcomes. We can give you loads of help about being on HT, what side effects are and how to counteract them, which is rarely covered by your consultant when you are put on it, but I'll post this response now in case you need to arrange a prescription before tomorrow. Feel free to ask us absolutely anything.
Something that's helpful when you ask questions is to keep an updated diagnosis and treatment bio in your profile, which enables people to give you more targeted advice. Include things like your PSA level with dates as well as your 'technical specification'.