leave my brazilian husband while processing my RNM card?

Not sure of your question; (Your posts alone makes me see "red flags" and I am not PF)
You applied for CRNM or have received CRNM? Should you separate prior to marriage you will not receive a card, because you will have to swear all information provided for CRNM remains true and in effect. (Never give false information).
If you leave/divorce and he informs PF, "red flags" will be raised and follow ups with you may occur.
Must inform PF of any change of address on a CRNM, again informing why and where.
Does not seem to be a happy marriage, so why take the risk of having CRNM cancelled and asked to leave

Well, you can still receive the CRNM as long as he doesn´t complain to the PF. If he does that, its a "red flag" as Texanbrasil said. That automatically hardens the disposition of the Policia Federal to investigate closer to see if your marriage is legal and not against the interest of their citizens and the state...

So take it easy on him and let the storm pass. You can always divorce after you receive the CRNM. But not right away because again, that is a red flag - like a "marriage of convenience." Say 2 years? Can you hack it?

If it´s really hell, you can always opt to go home to Bangladesh. So there´s a lot of things to think about.

I know its a terrible thing living in a foreign country with marital problems and perhaps without support
of close relatives and friends...

robal