I am by far not a world traveller or presume to know much, but I can say with certainty that I have never looked down on Nigeria or thought badly of it’s people (I’m from Canada) despite knowing the Nigerian Prince scams. There are scams everywhere and they are not associated with one country.
Also I have a colleague who is Nigerian (just recently moved here) and he is perhaps the kindest, most uplifting and happy person I know.
I am sorry that this is your reality and how you have to guard your heritage.