I have never been officially diagnosed as celiac as by the time they tested i was already gluten free. But I had years of pain then progressed to being housebound and wearing tena in my 20s for months as I lost control of my bowels.
The doctors weren't helpful, they offered me antidepressants when i broke down in tears in their office. I read lots online, decided to do the fodmap diet and eventually realised gluten was my main trigger.
I've been gluten free for around 7 years now. I went out for a meal somewhere I've been before with no problems. The manager saw my GF label and directed the food to me, I didn't question it as I trusted them. Unfortunately that was an error, it wasn't GF and I have been unwell for 3 weeks not being able to eat more than a banana at a time. My stomach is still sore but I have only in the last day been able to eat a meal without pain. The moral here is you can no longer trust places even if you've eaten before with no issues, if it looks like everyone else's or looks too good question it. I wish I had.
As for alternatives you get used to them. Warburtons are my favourite for bread products especially their tiger bread and wraps! Sainsburys chocolate chip cookies are my favourite biscuits (even not gf dds will happily eat these!) Aldi do lovely tempura chicken which is nice in a wrap with sweet chilli sauce! The finest sausages are lovely and gf, I make cheaters sausage rolls using those and the jus rol puff pastry for lunches. The gf couscous is nice and good for quick lunches, i cant remember the brand but i buy in sainsburys. Asda are great for alternatives, I do a monthly order from them.
We mostly eat natural gf so lots of rice or potato based meals. I don't really buy snacks except the gf cheese oatcakes, rice cakes, fruit and the occasional chocolate. Weirdly with chocolate I'm ok with cadburys but unwell with galaxy.
Another thing to be aware of is coffee shops as many use oat milk now which isn't always GF, so tell them so they can clean the spout between. Or go for things that don't use milk like the iced coolers or tea.