Hi Andy and welcome.
Sounds like you are probably LADA (Latent Autoimmune Diabetes in Adults). This is a slow onset Type 1 which is often mistaken for Type 2 in the early stages and sometimes even responds to Type 2 oral medication/lifestyle changes for weeks, months or even like in your case, years, but gradually the insulin producing beta cells are slowly killed off by the immune system and you reach a tipping point where the remaining insulin production is not enough to cope and BG levels can suddenly sky rocket. How did your Type 1 re-diagnosis come about? Did you end up in hospital DKA or did you just have a switched on GP/nurse who spotted it before it got that bad?
Which insulin(s) have they given you? That will probably make a difference as to what we suggest you can eat. For instance if you are on an (old fashioned) mixed insulin, you will probably need to stick to meals of set carb amounts at set times, but if you are on a basal/bolus insulin regime then in theory you can eat anything, with moderation.
We have another member
@DuncanLord who is relatively recently diagnosed and trying to get his PSV license back, so yes, it is a worrying time when your livelihood depends on it, but it is important to learn how to manage your levels with insulin before getting back behind the wheel, as insulin is dangerous stuff.
What sort of BG readings are you getting at the moment? Are you finger pricking to take readings or have you been given Freestyle Libre sensors?
Hopefully if you can give us more information, we can give you better support/advice.