TMN in my first year audaxing (and cycling) I think I must have been the lanterne rouge on every single ride so I do know just how you feel. Last year I was surprised to find that there
are people who ride slower than me, but not very many on a 200

. Even so, I have got to know a great many lovely people over the past year. It's now rare for me to do a ride and not find either someone I know who is also doing it and is happy to keep me company for a few miles at the start before racing off to catch up with the faster lads or else someone going at about my pace to ride with (even if they are taking it slowly so I can keep up). I think you and I ride at a similar pace. Let me know what rides you are doing. I'd be happy to ride with you if I can but in the event of a mechanical I can only offer morale support as I'm pretty clueless!
I'm a member of cycle rescue. It's about £30 ish a year I think ( it comes as standard with my insurance so I'm unsure of the exact cost). This provides peace of mind in the event of being stuck in the middle of nowhere with a borked bike. Confession time- I wrote my previous (carbon) bike off on the second audax I ever did with about 50k to go. I cracked the top tube falling off on the way down a hill. It got me back ok but it was like sitting on a jelly and shouldn't have been ridden. No amount of mechanical know how could have solved that one.
I always carry a Var lever. I struggle with tyres too.
As regards distances, the furthest I had ever ridden last February was 200k (and that near finished me off) and I couldn't imagine being able to do even a 400 never mind the rest. PBP was double the furthest I had ever ridden and my only 600 was
by far the easiest one of that distance in the calendar! At the time I rode the 600 I wasn't intending to do PBP so wasn't "in training" and wanting a tougher ride. The distance alone was enough of a challenge! I thought PBP was for the real long distance loonies and I wasn't capable of that! Martin Brice thankfully persuaded me otherwise. I've found the trick is not to look at the whole distance, break it up. It's only......km to the next control. Easy peasy I
know I can do that distance so
just point the bike and pedal as Arallsop has pretty much said. All you need is a bit of determination and a large dose of stubborness and before you know where you are the ride is finished and it was nowhere near as hard as you thought it was going to be!