Got a freestyle libre the other day

And it's shown my blood sugar is dipping to 40/43 and hovering in the 50's at night. Which (I think legitimately) has me a bit scared. I've only had it for 2 days, so I can't quite call it a "pattern" yet, but I'm wondering if I'm over reacting if I call my doctor on Monday and say "hey, so, can I get one of these that BEEPS cause 43 is kind of dangerous and I'm sleeping right thru it?" (Well, the first night was 40, the second night was 43. Both nights I slept thru it.)

After the first night of sleeping through the 40, I had a greek yogurt before bed last night, hoping that'd help, and I didn't have any lows till about 2am, but then my blood sugar tanked. /sigh/ Not sure what else I can do?

I'm a gastric bypass patient, so I can't exactly eat a hell of a lot, so there's only so much loading I can do. Maybe I'll try a cheese stick tonight? I don't know. Do I set an alarm for a midnight snack?

BTW, I have reactive hypoglycemia, not diabetes, but the hypoglycemia forum seems to be a ghost town and you guys seem super active and knowledgeable, so I hope you don't mind me crashing your party.