Hi. I’m not an AME but have some experience of colleagues going through a similar situation.
Firstly - try not to worry (easy to say, I know!). In the UK and I believe also in EASA (as the process used to be the same for both) then you can fly on a Class 1 while undergoing treatment and taking SSRI. You will be made unfit initially until the dose of SSRI and treatment plan is approved but as long as they are working out for you then you can get a Class 1 re-instated with OML restrictions.
If you are in the UK then the CAA have a specific treatment pathway that they will follow. It can be found here -
https://www.caa.co.uk/media/00lbz5lx...flow-chart.pdf
with more information available on the CAA website. I’m not sure about EASA but imagine that it will be similar.
Key points to note are that only specific SSRI meds are approved for ongoing use “ SSRI's: only CITALOPRAM, SERTRALINE or ESCITALOPRAM within normal BNF dose range are acceptable as maintenance therapy.”
You can only be made fit 1 month after resolution of symptoms; assuming the treatment plan is working then ongoing treatment (CBT/SSRI) is normally ok. Also, any change in dose will make you unfit again for 1 month.
So in reality you are looking at 2-3 months unfit as a minimum, depending how your treatment goes. To be assessed as fit, you will need reports from your GP or AME and also you will need to see a CAA psychiatrist for a final assessment. It is likely the CAA will also require 3 or 6 monthly visits to their psychiatrist during treatment.
Hope this helps. As I said it is UK specific and only a summary of similar cases. Every case is different so be guided by your AME.
The best thing you have done though is to recognise the issue and start to get treatment. It seems like a mountain to climb but you will get there. Good luck.