PCOS Weightloss - Where am I going wrong?

Desperate for help.
My diary is open and I'm happy if anyone could take a look with my diet and let me know where I may be going wrong!?

I managed to lose 3 stone just through diet and exercise and kept it off for around 2/3 years. In the last 12 months just due to stress and diagnosis with arthritis which meant I had to cut down exercise for a while - I've pretty much gained all the weight back.

I've tried to mix things up - Joined a new gym - I attend 4 x 60 mins sessions a week which is mainly weight training with 10 mins of HITT.

I'm on the highest strength of Prozac at the moment - 60mg
Metformin - 200mg a day

Recently had some test results to test for everything which confirmed I was Vit D deficient which i am now taking supplements for.

I weigh everything I eat and try to track everything I eat - Aim to drink 2 litres of water during the day, aim to have at least one protein shake a day - Vegan blend as normal protein shakes upset my stomach.

All my meals are high protein based and I try to have as little carbs as possible - mostly coming from vegetables or wholemeal rice/pasta/bread.

Currently eating around 1500+ calories a day and I don't feel hungry.

My weight fluctuates daily but weekly pretty much stays the same.

As far as I'm aware I'm doing everything I did last time and more - my diet is much better than when I first managed to lose weight.

My weight just doesn't seem to be shifting - although my muscle mass is slightly increasing and I am getting stronger but I've been the same weight for around 6 months now and I'm at a loss at where I'm going wrong with my diet as I know this is more important than the exercise mainly.

If anyone has got any tips, tricks, advice it would be so appreciated.

TIA x