adviceeee would like a guys opinion

So I started dating this guy who has been trying to date me for like 6 years now. I wasn't interested at first and then I started falling for him. I've known him forever but haven't actually dated that long. Everything was perfect like I legit felt like he was the one as he told me I was and even gave me a key to his house. This weekend I didn't hear from him much. He's a cop so I figured he was so busy working. I heard from him last night then didn't hear from him all night or day. He's read my messages and has viewed my snapchats. He even accepted a girls friend request on Facebook but couldn't even reply to me and say I'm busy or something. Obviously he's ignoring me. I've never felt like this towards a guy so soon and he's even said he's been in love with me forever. I just don't understand what could of happened. Why do guys just ignore you like that? 
Anonymous due to family on here.
Please no rude comments. Would just like support or other people's happy stories thanks! I understand he can be really busy but he's never not let me know he's home due to safety reasons . He's posting on snapchat so he def is ignoring me