I think buyers remorse is pretty common but the things you've listed don't sound that bad really.
It might make you feel better to hear we moved two years ago and I love the house now but hated it when we moved in.
On day 2 we noticed an increasingly bad smell by the front door which turned out to be fresh dog urine from the sellers pets.
We panicked a bit and ended up ripping up all the downstairs carpet as it was so disgusting. We lived with bare concrete floors until we could get new flooring laid and blew a chunk of money in getting it fitted within a week.
Two weeks later there was a thunderstorm and we found water trickling down the utility room wall. Turns out the flat roofed garage hadn't been maintained so we had to get that redone at a cost of £4k.
There was long term water damage in the office in the garage conversion too but it had been hidden by all the shelves and general clutter when we viewed.
The garage door didn't shut and so couldn't be locked, also the wind whistled through and it filled with leaves. Cost £2k to replace.
Bath in family bathroom isn't sealed so water started leaking through the hall ceiling when we started using the shower over it, I think they just hadn't used that bathroom for years. I resealed it but it needs doing again now, I think the bathroom needs redoing really as some of the tiles are coming off.
Kitchen is literally falling to pieces, finally getting it replaced next week which I am excited about.
Last year the fridge stopped working, on investigating it seems it was plugged into a broken extension lead that was sparking when moved so we were lucky no one had been electrocuted. When we dragged it out it was covered in a thick layer of greasy dog hair, big fistfuls of hair and dust, made me heave as I cleaned it. The kitchen cupboards tops were covered in the same stuff.
The worst one was the downstairs loo had leaked between us viewing and exchanging. They said it had been fixed but it meant there were no tiles on the wall and the sink was hanging off.
Unsurprisingly it wasn't fixed and was still leaking. Cost £3k to fix it and have it all replaced.
Despite all the current issues I do love the house now. It's in a quiet neighbourhood, near the park, no traffic noise, quiet neighbours and the living room is bright and airy and makes me happy.
You'll be ok, you just have to prioritise the most important things and get on with it. And try not to obsess about the old owners like we still do occasionally!