But It's absolutely not the normal "having a dig" thread and if I wasn't torturing myself about the situation I promise I wouldn't post it.
So I don't drip feed: I'm autistic and have an invisible physical disability.
The bus to DD's nursery was just a small one on this occasion and there was one wheelchair/disabled seat. The front seats have 'elderly' signs on and there's a sign on the wheelchair seat saying something like "This seat is for wheelchair users. Small prams and buggies may use this seat but must move if a wheelchair user needs access". Totally acceptable, I have no dispute.
So basically what happened was I got on to pick DD up from nursery, normally we go in the car but only DP drives and he was called to work. I have 6 month old DS in his pram (Silver Cross Wayfarer if it's relevant coz I can't fold it). I was in a lot of pain that day or I would have used his sling, i physically couldn't do it. In fact I kind of lean on the pram like a zimmer frame IYSWIM.
Pay for my ticket, park pram in the space and sit in the disabled seat. Every other seat on the bus is taken. Elderly people in the front seats. Halfway through the journey we reach a bus station and a lady in a wheelchair is in the queue, bus driver tells me to get off. Normally I'd 100% do this but I wouldn't have made DD's pick up.... She is only 4 so can't exactly wait another 30mins for the next bus.
I start having a panic attack with the situation and kind of splutter out that I really need to catch the bus. The absolutely lovely lady in the wheelchair says she's only taking her shopping home and will wait for the next bus.
Bus driver, assuming I guess that I'm just a snotty young entitled mother demanding the seat, continues to tell me to get off the bus. I start to cry.
I manage to choke out that I'm also disabled and get told "aye of course you are love, what kind of person takes a seat from someone in a wheelchair". It then felt like he was pitting us off one another, like some awful 'disability contest' saying things like "go on then what have you got, is it worse?"
The lady eventually gets through to him that she really isn't in a rush and goes out of the station so he can't just sit and wait for her. He reluctantly drives off with a shitty attitude and a grunt 
I don't know what I'd have done without her lovely calm demeanor. I'm still absolutely mortified that I didn't get off the bus though, if it wasn't for DD there's no way I'd have stayed on.
Totally prepared to hear I WBU, especially for starting a bus seat thread. But I can't stop thinking about it and have noone to discuss with IRL 
In hindsight I would have caught an earlier bus but usually they have big ones with 3 disabled/pram seats so I didn't think.