I would be concerned how much she is drinking too.
Can you return to IC to discuss how to handle your suspiciousness in a way that is healthy for you and leave her out of it for now? You sound like you are still traumatized from the affair itself, blaming yourself for that, and maybe you could use some counseling advice on that and the stress of living with a drinker and or partier.
You could do all of this without discussing or fighting with her about it.
Until you get some perspective on this, DON'T FIGHT with her about it. Especially late at night. Get a substitute activity like venting on this board or phoning a male friend if you feel on the verge of starting a fight. That way you can buy time to make a rational decision about what you need and want to do and you won't be shooting yourself in the foot in the meantime.
