I am a picky eater, have been a picky eater all my life. I managed during my late teenage years and early twenties to acquire a taste for vegetables (and I am grateful that I did), but fruits (apple, grape, etc) are still a problem for me.
I have identified however, that I like
Mango
oranges
lemons
Now I wonder what fruit I could "try" next. Preferably I would not start with Apples and Bananas (as a kid it was constantly suggested I should eat apple/bananas that I don't have the best memories in this regard, I think these will be tougher fruits to start with).
Why am I asking this? Ultimately I want to balance out my diet more and potentially get into a position where I can opt for fruit over chocolate if I want to have something sweet.
You seem to like citrus and tart flavoured fruits. Perhaps other citrus fruits such as lime and grapefruit, or pineapple would be something you could try.
Give strawberries a go. I discovered them pretty late in life compared to others, and they are juicy and flavourful in a completely unchallenging (for me and my difficulties) way.
Would sorbets make things more palatable? I ask as I recently took delivery of an iced treat machine and a mango sorbet was made literally from the contents of a jar of mango and mango syrup.
I sometimes freeze grapes and crunch through them in Summer.
Berries are probably a good choice, they're a bit tart which I suspect you lean towards given you don't seem to mind citrus. I wonder how you will go with lychee - this can be purchased by weight, but I actually buy cans of it to blitz with ice to make a slushee.
I'm not sure if texture is a problem - if it is, blitzing into iced treats is definitely my recommendation.
Fresh cherries! 15 cherries contain about 75 calories and you have to eat them mindfully because of the pits, so you can't just snarf them super fast. This is actually my new coping mechanism for the munchies lol
On the subject of apples and bananas, would they be acceptable if they were in a form such as applesauce or if the bananas were whirred or as dried banana chips?
A lot of fruits are closely related, like, oranges are actually a hybrid of mandarins and pomelos, so maybe explore a few fruits from different types. If you like nectarines maybe you'll like peaches and apricots. Raspberries/blackberries etc.
Not sure where you live but there are some great tropical fruits, pineapples, passion fruit, lychees, mangosteen, star fruit. I'm biased towards lychee cause we have like 20 trees and they're tasty.
I'd just find a good grocery store produce section and check out different fruits, go by smell, maybe ask if they'll let you sample some. Sounds weird but I worked in a Safeway produce section for a while and the managers encouraged us to cut samples for people.
Persimmons are nice, just keep in mind that they are quite rich in fats. Also, supermarkets frequently sell them under-ripe because they look better, but then they are quite bitter. Look for ones that already have some soft spots, that's a sign that they are sweet and ripe.
try smoothies! fruits/veg can be difficult to start to like due to texture but blasting everything into a smoothie can make it easier. try mango and yogurt, then maybe berry and ice, maybe mango and banana to get used to banana, etc.