I am in Group 1 and I have actually found the the Group 1 OPM is someone who will listen when you have a complaint. I believe that he genuinely wants to improve things for crew at LGW.
I am guessing you are Group 2 as you say you go back tomorrow, what are the initials of your OPM, or failing answering that with the initials are they nice or not?
Have all your periods of sickness been in the last 6 months? They only count for 6 months and it is a rolling 6 months. Any wellbeing or disciplinary chats can not refer to things from more than 6 months ago as they are technically off of your record once 6 months has passed.