Retainer woes… What to do?

I have bruxism (I grind my teeth while I sleep) but I also have to wear retainers to keep my teeth straight (I did the Invisalign treatment and I’ll have to wear them for the rest of my life at night.)

Initially my orthodontist gave me two hard plastic molds to fit over my teeth. After grinding through the first top one, it finally broke. So they replaced it with one of those retainers made with wire and a bite plate. It cost me $94.

Not much longer after that, my bottom hard plastic retainer broke. Since then I’ve been using the last invisalign tray I had during my treatment and it’s been holding up all right.

And now, once again, I woke up this morning to take out the top retainer and noticed the wire was snapped. :/

Has anyone else had this problem? What do you recommend? Or am I just going to need to bite the bullet (no pun intended) on getting a new retainer every 6-12 months? Thanks for your help.