I will do my best to put all sense of ethics & morality aside (since you clearly won't listen to it anyway), and try to give you pragmatic advice (for which I will probably be downvoted into oblivion, but whatever):

Your boyfriend has no right to ask you to stop having sex with your husband. If he wants to claim that right, he needs to get a job and be willing to marry you after you get divorced. He needs to do this regardless of how his family will react (as you mentioned earlier that was a concern with them cutting off his financial support if he did this). If he's willing to do this for you, then go ahead & divorce your husband to marry your boyfriend. If he's unwilling, then break it off with him because he'll never commit to you. For the love of all that is holy, keep up with your birth control.

You personally need to work on becoming financially independent, because at this point it's only a matter of time before your husband finds out about your affair & kicks you out to go back to your parents' house. Consider updating your passport & getting a work visa to a foreign country that doesn't frown on divorced women living on their own if you can't stand living with your parents. Once settled in that new country, cut your husband loose & grant him a divorce, since he deserves a better & more loving life partner. If your boyfriend is still serious, he can join you in your new life.

On that note, I can't fucking believe I just typed all that shit out. But at this point the best thing for all parties involved is to figure out how to minimize the damage being done to your poor husband. I have been cheated on by a spouse before, and it makes me sick to read these posts.