Aio for pretending to cheat on my gf

So for awhile now I been feeling like my girlfriend or her family members or member have either been following me or tracking my location and tracing my conversations but when I ask she never says anything except that nobody’s hacked or whatever and im tripping but for months now almost 3 to 4 days a week something is changed in my car it’s been moved or something ect . Recently we were home an I overheard a conversation about something I was put exactly doing now this isn’t just a coincidence as it’s happened on more than one occasion an when I’ve walked into a conversation I’m not supposed to hear her mom got all silent one time her mom misspoke an slipped about a haunted house and the next weekend after she somehow had a different shift and I had to work.. I figured I knew who she may be with an calls an of course he was at a haunted house I feel like I’m in this crazy triangle and was the option not the want an she’s tryna make me seem crazy and act out or something… idk I decided to make a fake texting number an looked up hook up sites to see if a silent convo would take place an sure enough it did smash idk what to do but had to figure it out