I've had a guinea pig and he never bit me. Not once. Only licked. He trusted me and I made sure he had a good life. He was outside and free to roam the garden until dusk. And inside the home if the outside was too cold/dark/wet. The garden also offered lots of plants to eat and hide under. He had great avriety in diet alongside the petfood and guineapig essentials. He would join me at the dinner table with his own plate of safe greens. We would snuggle every day. Everytime I had to catch him, it sometimes turned into a chase. He ofcourse didn't want to go into the cage. The cage only served to protect him against predators at night, and from our electronic cables. Which ofcourse he didn't understand. But he still accepted me picking him up when catching him. No biting. He knew he'd be free again come morning. He died how he lived after my dad let him out and left him outside overnight because he couldn't catch him. My only regret is that I didn't know they had to come in pairs.

So what in the fuck are you doing with that guinea pig that it distrusts you so? I literally had to chase him sometimes and he still didn't bite me when I gently but quickly scooped him.