As discussed in another thread, please do not make a generalized stereotypical assumption about African men.
Men and woman of all cultures and races cheat and are dishonest.
I have met very loyal Africans that care immensely about their children and wife and family means everything to them and they work very hard to support them.
I am very sorry that you are going through this, it is terrible to discover the man you thought loves you is trying to find another relationship.
Been there done that with an American man after many years of marriage.
Sounds like he doesn't want to work things out. You can try counseling. You have the option to divorce him and notify USCIS in writing.
It takes a closer look to find a man you can trust. In my case being of the same faith has given me a comfortable way to gauge the relationship.
I don't date men that hang out in clubs or bars. If their lifestyle, values and morals are very different from yours then look elsewhere.
Don't try to change someone, it won't work.
Many relationships fall apart, so do cultural diverse marriages. Was it for the GC.........only he would know. Marriages fail for all kinds of reasons.
Many couples share email passwords and an open computer screen.
When my American ex barricaded himself in the basement with the computer and boarded a window shut it definitely gave me a clue of what he was up to.
It is in the personality, not the culture, not the race.
Don't fall for someone too soon and test around a little, watch for subtle red flags, minute details can tell a story sometimes.
Associating an entire continent with one man that has cheated on you is not wise and is unfair.
For every one that cheats there are many that don't.
We just have to be a wise to watch for honesty in potential mates when we first date them and build from there.
Can we do all that and still get deceived .........yes.
I wish you the best and may your heart heal soon.