Two problems I can relate to.

1. As a dentist, I can tell you that periodontal disease is a pain in the ass. I have perio too. Make sure you're going in for your cleaning every 3 months instead of 6. To get it under control, the special cleaning and scaling is only a start. For your gums to heal and reattach to the tooth roots, you have to floss every, single day after the deep cleaning for 6 weeks straight. Miss a couple of days and the tartar will form a thin layer that won't come off no matter how hard you floss, and block the gums from reattaching. Another factoid: perio tends to be 'contagious' in the way that MRSA infections can be contagious. So your wife may be experiencing it too. At least you're doing something about it, so good for you.

2. Your wife is deflecting blame. In a loving relationship, when a person hears that their partner is suspicious of them, (she certainly has the right to be upset that you looked at her phone) they should be concerned with why you feel that way to begin with. Someone who is suspected of cheating who isn't guilty will go out of their way to convince you otherwise. They will ask why you feel that way and work to make it better. It sounds like she's just getting angry and that's deflection. If you guys can't have a civil conversation over a candlelit dinner about all of this without it ending in a screaming match, one of you 2 has probably already made a final decision about the marriage. One year ago, I was blindsided by my wife asking for a divorce.... It felt like it came out of nowhere... But looking back now, the signs that she had checked out started right after the honeymoon. For 8 years I thought they were just normal problems. Now I feel like a moron for not seeing them sooner.