Hello fellow Postgrads!, I am a first year PhD student into my study 7 months already. I had a milestone "deal-breaker" assessment due 3 months into my research. That assessment is usually relatively easy to pass and its just an expanded version of your proposal with which you applied. However, my supervisor changed my topic and asked me to rewrite a proposal, which I did he was never satisfied with it and kept making me re write it until time for the deadline was close. I submitted it like that and I failed but was given corrections and a second chance, he changed the topic again, and made me redo the whole thing from scratch. Which I managed to do, however he said he doesn't like the structure and made me redo the hole thing again and added more research areas to it. Basically I have one week to do the work of 3 months in a felid which is way far from where I started. Is this normal supervisor behaviour? I honestly feel like quitting. I feel my supervisor is making experiment on me if I am able to do quality work in minimal time frame, but this is unfair because my admission is at stake, and my mental health. Does anyone else experience this?'

This is odd behaviour and might indicate 1 of 2 things.
Either the fault lies with your ability or your supervisor is a nightmare.
Either way, it doesn't look good.

It might be time for you to consider throwing in the towel and trying elsewhere.
If your supervisor is a nightmare at 3-7 months can you imagine what they'll be like over the next 3-5 years?

Who was it who marked your failed assessment? Was that your supervisor or another member of staff?

No, it isn't normal. I'd think / talk to someone about switching supervisors. It'll only get worse. I wouldn't be doubting your abilities. This isn't normal!

Ps. If you do decide to talk to someone, it is probably best not to criticise - no matter who it is you talk to (unless you know you can trust them!). If you want to switch supervisors and/or projects it might be best to say something about realising that actually you are really interested in X and would love to work on X/Y with Z. Not sure if this is even the way you might decide to go, but just wanted to add to my earlier response in case you do!