you can still do everything you usually do, but in moderation! my arthritis causes me chronic pain, which is not fun but i have learnt to live with that and take loads of meds to alleviate things. i can't walk/cycle as far as i used to, but i still work as a nurse and have to rest adequately to ensure i am fit to work. if i do things like paint the living room in a day, it causes agony and lots of swelling for a few days, but it does recede after a while. the less fun part for me is falling up and down stairs at times, tripping up and banging into things - i have definitely got more clumsy since my diagnosis. it is frustrating if i have a 'droppy day' (where i drop absolutely everything i pick up) but can be fun if i pass things to people and end up throwing stuff at them instead!
no foods or supplements will help. meds will, and so can physio, gentle exercise, massages and acupuncture (but everybody is different!). it is life changing and a lot of hassle......but you will learn to live with it and alter your daily living/routines to cope with it. my ONLY advice is to be good and take all of your medication (keep going back to your gp to get meds right, or request a referral to a pain clinic if it is bad), pace yourself with all activities (it will be no good stopping and starting intense periods of activity, work or exercise- it will just hurt and cause swelling/oedema), and be kind to yourself - learn to relax and take periods of rest where you do things that make you feel good.
and if you find that your illness takes a toll on your mental health, fess up and tell your gp, get it treated. depression and pain are intrinsically linked in the brain and they fuel each other; the more rubbish you feel, the more pain you will experience; and the more pain/struggles you have will make it more likely that you will develop/increase levels of depression. i have both and take 34 pills a day......but i will carry on with my life and do as i please. yes my life is more difficult now, but planning ahead and taking more time helps enormously - i will be dragged off kicking and screaming before i give up on my life, what is important to me and letting my illnesses win.
google your illness, coping strategies, medications and talk to people......knowledge will help you decide how you want to manage things......and try everything you can until you find things that work! it will be ok, but it is obviously a shock, very new to you and a it overwhelming. but you can have this illness, an still have a life. good luck x