Reddit mentions of Small Pet Select 3rd Cutting "Super Soft" Timothy Hay Pet Food, 10 Lb.

Great, thank you for being such a good person and taking him in, that's a very admirable thing to do!

You seem to be intelligent and you're probably doing your own research. Good job on trying to find him a friend, I cannot stress how important that is, as you've probably read online.

The scared phase is typically just a phase in the beginning. He's in a new environment and he's afraid. Guinea pigs are prey, it's only natural for them to jump and run the second they see movement they're non-familiarized with.. even when it is familiar, they're not the brightest creatures in the world and can still overreact to slight movements. After this scared phase, which can really last from a couple days to a month, it depends on their personality. Some piggies can be chill and start wheeking whenever they see their owners, and others will simply run from them for the rest of their lives, even though they enjoy being cuddled once you finally get them in your hands. It's simply something you're going to have to go through, and don't take their fearfulness personally :)

What kind of dry food are you getting him, and what kind of hay? What type of water holder do you have? He may be unfamiliar with it. Keep giving him lettuce (not iceburg) if he'll eat it, but not too too much. 1 baby carrot a day and a little bit of green pepper should do the trick as well. Piggies are supposed to have a little salad every day. Here's a fantastic guide to what they can have and what quantities is recommended.

Regarding his bedding, the only way he'll stop being afraid of you is to see that there's nothing to be afraid of. It's okay to scare him, since he'll eventually learn that there's no reason to be scared. Just clean around him and provide him a little treat like a carrot and he'll eventually come around. My piggies run from me whenever I clean their cage, it's just apart of owning them.

I don't know if there will ever be a point where a piggie can "trust" you. I don't think they're capable of trust, though some have very relaxed personalities compared to others. Like I said, they're prey. They're built to not trust you. You can start touching and holding him whenever you'd like, though you know your piggie better than we do. If he's truly so afraid of you that you don't want to hold him, don't. If you think it's time, go for it, he'll run, but just grab his butt and give him a nice cuddle session. Don't wear any clothes you're fond of :)

Whats most important is that you get him a friend, a large cage (2x3 minimum for 2), and understand how to properly feed them. I highly recommend purchasing this hay (I know it may seem like 10lbs is a lot since your little guy is hardly eating, but you'll be shocked to see how much they eat normally), these pellets (I assume he's under 6 months old), and using these kind of water bottles. I also recommend buying fleece bedding, as you will save money and time cleaning in the long run.

Let me know if you have more questions!