Could I be his side girl?...

I'm scared.. I've known my guy for over a year, we dated once already but it was bad timing on both our parts so we went seperate ways stayed friends. About 4 months ago we tried again, and it was always weird.. He'd have his friend drop him off at the corner of the street and he's walk to my house, or park on the street atleast 3 houses away from my unused driveway and street parking spot. I've found bruises on his neck once and when I asked him he said he fell... On the side of his neck... I let it go. Recently he's been disappearing, he'd just stop texting me for a few days and come back like nothing changed and like I wasn't looking for him. We see eachother maybe twice a month, and talk on the phone once every few weeks.. I'm craving his attention and he says sorry and that he wants to see me.. But nothing ever changes. His fb relationship status is taken, but he refuses to tag me as his girlfriend or even let me tag him in pictures or posts, claiming it messes up his Facebook account. I use to receive a selfie everyday from him, but he's started to come up with half assed excuses why he can't take them as offen, either his phone is crappy, he doesn't look good or he just woke up and. It's always some kind of excuse. He won't call me his girlfriend or tell anyone about us (including his family! Whom I've yet to meet) because "labels don't make a relationship and it's no ones business that we are together." We also haven't been out in public in over a month, which was for my birthday.. I'm in love with him... And I'm scared.. What if I'm not his only girl...? Advice?