Hi OP. I agree with others that I think getting signed off for a few weeks will really help you to just take a step back and breathe. It sounds like you’re in a bad place at the moment and are overwhelmed, so taking the stresses of work off your plate for a few weeks will give you time to try and get yourself back to a more comfortable place to formulate a plan for moving forward.
I agree with others however that getting signed off for 7 months would likely be close to impossible. That’s just not the way GP’s typically work. Sick notes are usually only given for a few weeks at a time, and if you need an extension, the doctors usually want to try other things (eg. medication, therapy etc.) before just automatically agreeing to keep giving you more and more time off.
I’ve just returned to work this week after a 6 week absence. I’m pregnant, and have been incredibly sick during the first trimester. This is my second pregnancy, and the same thing happened with my first, so I knew what to expect - very very ill during the first trimester, and then magically absolutely fine once I got into the second. I told my boss what was happening and she was very understanding (she remembered my situation from my first pregnancy, when I also needed time off) and basically told me to take until half term off to rest and try and get myself better (I’m a teacher). I self certified for a week and then went to my GP for a sick note. Told them what my boss had said about half term, but they refused to give me a note for that long (at the time I first went it would have been 7 weeks). Gave me an initial note for 3 weeks, and asked me to try a particular anti sickness medication. I did, it made absolutely no difference whatsoever, so at the end of the 3 weeks I had to go back and ask for an extension on the note to get me through to half term. They gave it to me, along with another medication to try, but I’m almost certain that if I’d gone back a third time and tried to get it extended again I would have struggled. I actually went back a week before my note ran out as I felt better and like I could manage being back at work, but if I hadn’t I would have been very aware that I would have likely struggled to get any more time than the 7 weeks they’ve given me, over 2 notes. Obviously your situation is different as it’s mental health not physical, so your GP may be more lenient, but just wanted to share as my experience is very recent, and I was actually quite surprised how much resistance I faced in getting both the note and the extension.
In your situation I would get a note for a few weeks, use the time to try and get yourself some rest and recuperation, and then formulate a plan for moving forward, whether that be dropping hours, asking work for support e.g. see if they can lighten your workload a bit, looking for another job, etc etc. I just don’t think a plan of taking 7 months sick leave is a one to rely on, as I think you might find it’s actually significantly harder to get that much time signed off than you may be aware. Good luck OP!