I agree with redvelvet, I don’t think this situation is as simple and as black and white as it seems. Clearly the OP and her SO love each other but unfortunately sometimes love is not enough to make a marriage work. The in laws issue obviously doesn’t help. But 6 years of a relationship comes with a lot of emotional ties and it can’t be easy to take a big step each other way.
OP I think the best thing for you is to pray and take some time out to heal yourself, you need to go to therapy if for nothing else than to have someone else to confide in and talk to. Work on getting yourself healthy mentally first and then inshallah you will be able to figure out your next move with a clearer head.