Help! Semi Automatic 2006 possible gearbox issue

[Rebeccac]

Hello!
I have a 2007 registered Toyota Yaris, semi automatic. Had her almost a year now. On Friday, I was driving and 5 minutes from my destination, she randomly started sounding like a motorbike honestly! It was as if I’d had her modded.
She seems to be struggling to get into the right gear herself? It seems more going down than going up. I tried to manually move gears myself and when I put her back into auto, she shot right back up from 2nd to 5th. She’ll be going 5th doing 10/20mph. Had her MOT the day before and everything was fine so just really unsure and anxious as to what this may be / the cost of this.

Anything welcome!