I'm so sorry that you are feeling all on your own!
I'm in the US, so this may not be helpful in the UK.
My first stop for issues is calling my surgeon's office. He has assistants I can share problems with (and photos of my stoma via email) and they can either give me advice, send in a prescription or book me for a blood panel, get back to me after they talk to him, book me with his in-house stoma nurse or book me with him.
If they felt like I needed immediate help and I couldn't get an appointment, they would tell me to go to the ER.
Be very careful with what could be an infection! After my first surgery on 5/11, I was sent home after 8 days. I never quite felt like myself and soon started throwing up and running a fever. Long story short, I waited too long to ask for help and had to go to the emergency room for a second surgery on 6/1 due to an infection leak in my body that was days from going septic and me becoming critically ill. I now stay in close contact with the office if I sense issues and they call me weekly for a quick phone check-in.
If your body is telling you there's a problem - it hurts, looks irritated, or you just have that feeling something could be wrong, make the call to your surgeon or the local ER. Trust your instincts and know that you may have to be aggressive (in the nicest possible way) to advocate for yourself.
Finally, write down your how you got to where you are story so you have those details (why surgery, when surgery, any complications, what meds, how long meds, what following issues and follow-up appointments, etc.) when asked. I couldn't remember much after my surgery so now I have it all written down for when it's needed and update it ongoingly.
Hang in there!
Elle D.