I'd post over on Legal and ask about this, as it's a complicated situation in legal and financial terms.
It's been a very long time since I studied it so I could be misremembering -please don't rely on this at all - but I'm under the impression that a wholly innocent party in a bigamy case can, in fact, claim financial relief against the guilty, as s/he believed in the marriage as lawful. It's an anomaly, as cohabitants have no such rights and they too are living with someone to whom they are not married, but the detrimental reliance of the innocent party on the validity of their marriage certificate may be why. The key part is that he can't claim it was just a spiritual ceremony or something, and that you knew it wasn't legally binding. If it was a legit marriage ceremony and he lied about a previous wedding, then you, as far as I can remember, have a claim. I don't remember if you can claim in the same way and as much as a legitimate spouse, but I do think that you have grounds for some form of financial settlement - and it's one way; he has no such claims against you, as the guilty party.
When we got married, the registrar told us they'd caught people out more than once by remembering a prior (denied) marriage, checking, and uncovering attempted bigamy at the same registry office! It seems it's more common than people think. Horrible, though, and I'm sorry if this is what you are dealing with.
If he was married when you had the wedding ceremony, then your marriage was never lawful to begin with: it's a void marriage. That's not the same as one that say was never consummated, which is valid unless one party seeks annulment on those grounds, when they can claim it as voidable. In that case it's lawful unless one of the two says they want out on those certain grounds. But if you're too closely related, or one is underage at the ceremony, or one is already married, then it's void from the start.
I'd seek legal advice on this from a specialist, if you can afford it. I'm pretty sure, as I say, that you can seek financial relief if it would be unjust to deny it, in this circumstance, but I have no clue what the process would be or what the limits are.
If, on the other hand, you earn as much or more, or any house/tenancy is in your sole name, then the void marriage with you as innocent party is very useful to you as he is now legally only a cohabitant.
None of us can help you beyond finding out whether he was married, because you need to know what the law is and where you stand. I'd get the certificate checked out first, and then go from there.
Really sorry. This must be a horrible shock.