Picky Eaters: How can a picky eater eat healthier?

So I'll admit it, I'm a massive picky eater who probably never really eats fruits or veggies like I should. This has lead to me eating really unhealthy since forever and It's mostly because when I try to eat stuff like Salad, apples, bananas and more.. I just gag it up making me not able to eat it..

How can I get over this and finally eat healthier? I really need to and its costing me my health to not! I'm already a prediabetic and i am not wanting this to progress to type 2 because of my own stupidity.

I don't wanna end up having to poke my finger like 5 times a day because doing it once or twice like I do now sucks! (My doctor prescribed a glucometer for me to check morning and before bed)

Updates
2 mo
I'll add, I don't gag by choice! I don't know if it's related to my disability or not (ASD), I can't figure if its texture or flavor or something.. But it does happen..
Picky Eaters: How can a picky eater eat healthier?
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