I have IBS and OAB

Thanks for reaching out. Have you ever met with a Registered Dietitian? They may be able to help you with more specific diet recommendations unique to you. In addition to speaking with your doctor and/or Dietitian, these articles may be helpful: https://irritablebowelsyndrome.net/diet-management, https://irritablebowelsyndrome.net/clinical/bladder-problems and https://irritablebowelsyndrome.net/food/frozen-meal. Please reach out anytime with questions, we're here to help. Best, Kelly, Irritablebowelsyndrome.net Team Member

I apologise, but I don't know what OAB is.

Kelly's idea of seeing a dietician is a great idea. I would do that if you can. It will be worth it.

It's awful to not be able to eat enough good foods. Not just because we're missing out on foods we love or are used to eating, but because if the diet gets too restricted we risk malnutrition. But most of it is about the inconvenience, the symptoms if we go off course, the difficulty eating out or with friends and family...etc.

I used to be vegetarian, but all that vegetarian protein (beans lentils tofu etc) suddenly was my worst enemy. I have IBS -D.
It's a long story and I won't bore you with it, but I found the plainest foods had to become my new normal. For me that meant, fish, eggs, (plain cooked), vegetables (steamed only, not raw),rice, cous-cous, peeled potatoes, Italian ciabatta toast, plain cake, occasional stewed apple or peeled grapes. I could even manage some fries (chips) The only seasoning I can have is salt.
That's all easy to do at home for myself, but you can bet that when I go out anywhere, simple things like that will be impossible to get or ask for. That's why I only ever eat at home. One friend understands and always cooks me the same thing: salmon steak, white rice, hard boiled eggs and the teensiest bit of lettuce. But other people don't 'get it' at all. And many foods have things in them that are not good for me. It's very complicated outside of my own 'coccoon' !!
I also found taking a multivitamin/mineral complex and a B complex daily, and at times, liposomal vitamin C, prevented any malnutrition during times when my diet was limited to white rice, green beans, and eggs (that's during flare ups)

Wine is a complete no-go area for me. So is beer or any other alcohol except a tiny bit of brandy or vodka. I am OK with honey so add that to the drinks to make them taste nicer.

It is a horrible shock, and a change for you but if you start eating very plain cooked vegetables and proteins with some 'safe' carbs like rice, potatoes etc, you may be able to get quite good nutrition even though there are many things you can't eat yet. Keep it really really simple, unseasoned, stay away from onions, onion powder, garlic, and see if a plain diet helps.
If you improve as time goes by, you may be able to add some foods you like gradually, and see how they suit you.
I also get periods of normality when I can eat more variety. But flare ups really mean a tiny range of safe foods for me.

But you need a dietician if possible.