There is nothing wrong about an IQ difference.
Where there are problems is when the higher is annoyed by the other needing explanation or the lower having a complex about needing the explanation.
If you love it when you don't get it and they can explain it in terms you understand and they love it when they can fulfill your curiosity, perfect.
If you hate how they make you feel stupid or they are annoyed that you just don't get it no matter how they try to explain it, that is a problem and either party can be at fault in both cases. There is the old saying that if you can't explain it properly, you don't understand it fully, I feel that applies.
Talk with them, be honest and raw in your thoughts. Express your concerns about how you, as you are, may be less than they deserve. If they love you, they will try so damn hard to express themself so that you understand.
You shouldn't be asking the internet, ask them. Your insecurity or anxiety is not for us to cure, your partner is the only one that can beat that into your thick little skull. I joke, but really, there is no comfort or validation strangers on the internet can provide that beats your partner saying how much they love and appreciate you for you regardless of your flaws or shortcomings.
I battled that gammatical quagmire. I googled it and may have drunkenly misunderstood, or perhaps you are wrong, but it is almost certainly me because Google AI results are less than adequate.