I hate what i did! I cheated on my wife and i want to kill myself

I fucked up so bad! A little over a week ago i cheated on the most wonderful person in the world, my wife. She is so beautiful, she means the world to me and we love each other unconditionally. So i dont know why i did what i did. Im gone for work and i went to a massage parlor and received and gave unprotected oral to the lady that was giving the massage. I hate my self so much for this! I cant sleep i hardly eat. I just wish i could take this back and what scares me most is that im afraid i got an std from this. Im going to get tested before i reunite with my wife again because idk what i would do if i gave her something. I want to tell her what i did so badly but it would destroy her. Idk what came over me that night she's absolutely amazing im crying as i write this. Im debating on not telling her if my test comes back negative but how could i live with this guilt? If it is positive ive been thinking about not telling her and ending my life because i couldnt live without her or knowing that i hurt her this much. Id rather die knowing that she loves me than live a life without her. I know thats selfish but i cant. Maybe just disapeer somewhere but than id have to live with the guilt still idk what to do.... please help