All law (that passed by a legislature or your county, etc) will usually supercede a union (or other contract) if the contract terms are contrary to law.
Let me give you a nutty and obvious example. If your union contract says that you must kill one person per year, it'd be pretty obvious that that provision is contrary to law.
Other terms may be subtle.
Moreover, there's a big question here regarding whether or not the union violated the terms of its contract to represent YOU. They will probably argue that they were acting in the interest of the public good in some way (for all the members).
You may not like what I'm going to suggest, but you may want to find an attorney to coach you, if not all out represent you. An attorney who is coaching would have a limited role in your case (as much or little as you want to pay for), such as reviewing documents before you file them, to make sure they're written as well as possible. Otherwise, you're sort of like David going against Goliath (spelling?).
Let me tell you that if you decide to amend your complaint and include another defendant, you not only have to serve the new defendant, but must also mail a copy of the amendmended complaint to the attorneys representing your first defendant (you must cc defendants on everything you file in court, preferably with a copy date-stamped by the court).
Please let me know if you want links to such things as the employment attorneys' association or the trial attorneys association.
Otherwise, do not hesitate to write back if I can be of any further help. Meanwhile, thanks for accepting!