Clearly, there IS a logical reason for your reluctance to get back on your horse given that the last time you rode you felt threatened. You know what they say though, get back in the saddle immediately ASAP after a fall or a scare (given that you haven't been badly hurt). I certainly don't think that you should throw caution to the wind, but it's easy to blow things up into huge concerns the longer you worry about it. I think that you should get on A horse as soon as you can. You mentioned your husband's dead broke QH... get him out and see if you can just go for a mosey in a secure area (pasture, arena).
Part of your fears may be helped by taking a few lessons with someone who can review safety maneuvers such as the one rein stop with you. With something like the one rein stop in your arsenal, you may be less likely to feel as though you are at risk of losing all control.
Most importantly, DON'T resent yourself or tell yourself that you're being stupid when you feel that fear building up. It's perfectly natural to be nervous, but rather than feeling like you need to shove that fear away, try to accept it. Accept the fact that you are fearful, and work proactively towards resolving it. Stay as positive as possible... it won't help anything if you're beating up on yourself!