Looking for advice and comfort

[PT33]

Wonka,
The end of April I found out she was talking to someone.
I overheard her talking late at night.(I moved into the guest room by this time) I checked the phone records and she talked to this person at all times, late at night, during the day for hours. I figured out it was someone she had met at her new job a month ago.
I was devastated, because everything pointed to her cheating on me. I confronted her and she said it was a friend that was straight that was going through a divorce. She has denied any affair, emotional or physical up to this point. She told that she couldn't even think of being with someone else with what was going on. I want to believe this, but it hard. I have chosen to believe her because it doesn't really matter at this point. I know she still texts, but she separated our cell accounts the end of may. I'm pretty sure she still talks to her. She is constantly on her phone and does not let it out of sight. Also changed passcodes. she said it freaked her out that I looked at the phone records

We own a 4 bedroom house together and my sister moved in a yr ago. I went into the guest room a few weeks after this started in April. She is in the MBR. I tried early on to come back in our room because I took some advice from family members, that didnt go so well.

Having my sister here has made things hard because they have also became best friends over the last few yrs. This has really complicated things

I am having a hard time detaching, but have been trying really hard to GAL. I care so much and love her so much that Im having a hard time not caring even after everything she has done and how she has treated me. I'm trying to treat her like a roomate, but because I am a person that has never been able to hide my emotions it has been hard. Some days I do better than others. She knows me so well that even when I think i am doing a good job hiding my feels she knows that something is wrong. I wish I was a better actor