I work in the industry and started late (in my mid/late twenties). I can only speak for LA, but here's what I can tell you:
-Everyone starts as an assistant or a PA/"gopher"/runner. Unless you magically sell a script or have a VERY specific set of skills that let you be a consulting producer, you won't start anywhere up the ladder. You can expect to make just over minimum wage for anywhere from a year to four.
-Film school doesn't really count for anything. The industry is really only interested in your practical, professional resume. In fact, I know coordinators/Production Managers who refuse to hire film school grads because they often (not always), have a sense of entitlement on set and refuse/avoid the basic responsibilities of being a PA (taking out the trash, getting coffee, etc.). You may have a leg up on gear and the theoreticals of film/TV, but there really is no way to get experience without working on a professional set/production office. "Excellent communication and organisational skills and creative flair" are great in theory, but no AD wants to face off with your creative vision when they need something done. Organization and communication are important when you are working in the office, but you need to work within the confines of your supervisor's needs and the structure of the production at large.
-Expect that there will be long periods of unemployment. For many people, this ends up being the dealbreaker, more than the 18-hour days, the time away from home, and the weirdness of the people. I've gone 6 months between jobs before. I had to pick up the types of jobs I had in college to get by. Every job feels like your last. It changes your interaction with friends and family.
-The good news is that once you move up, even one rung, you will nearly double your PA rate. Money at the mid-levels can be really good, and only gets better the higher you rise.
If you don't think you can take a low-level job and move to a hub city, you are going to have a nearly impossible time ever working in the industry. It sounds harsh, but the truth is that if I need a PA to start in 2 days and they live in another city, I'm 90% likely NOT to hire them. It's too risky that they will need to make a long commute daily and get stuck in traffic, oversleep their alarm, etc. I also would be legitimately concerned about their ability to drive safely for a long distance after several 18-hour days with commutes both ways. PAs have died after falling asleep behind the wheel--I don't want someone to have to stay awake for an extra few hours just to get home.
I don't know how much production is happening in North England, but I can guarantee you that if you don't want that entry-level, low-paying job, someone else desperately does, and will do anything for it. If you can stick it out for a year or two, you will be on track.
Best of luck!