First ever post, so please be gentle!
I was recently diagnosed with an illness that will affect me for the rest of my life. I'm broadly ok with the news; I have very mild symptoms, and it means I can now get proper treatment (after thinking I might be imagining it for years) 
However, I've been told I should make some changes to my lifestyle; if I manage to do them all and get as healthy as possible, I might be able to control my illness with fewer medications (some of them have unpleasant side effects, so I'm keen to do this).
I've already kicked my occasional smoking habit since I found out it can exacerbate it, but I really need to sort out my weight (I need to lose at least 2.5 stone
) and exercise (currently almost non-existent). I'm a total comfort eater, with a love of anything bread and cream based, so this feels like a bit of an impossible task! I'm a decent cook, but mainly in French and Italian cuisines - aka, carb, cheese, and pudding heaven! 
I know that any changes I make will impact on my partner and friends - I'm imagining more boring food, less time for fun because I'll be food prepping or exercising, fewer nights out
- and I'm worried about how to keep some sort of balance. I'm really keen to make bigger changes rather than slowly-slowly; I know not to crash diet, but I'd like to be able to show decent improvement in my overall lifestyle by July, when I next have a hospital appointment.
AIBU to prioritise trying to sort out my health - even though it's not critical for me to make big changes, as it could be managed with medication?
If not, AIBU to ask for personal success stories, tips for big lifestyle changes, or warnings for what to avoid when doing so?