My hamster is acting strange!!!!

Okay so this is rhino, he's been a loving hamster and an active hamster since day one, today i recently gave his enclosure a new upgrade and i noticed this behavior from him, he would run on his wheel for a minute or so and suddenly stop and lay flat on it, he's never done that before and at first i thought he was dehydrated and i directed him to his bottle but he didn't drink anything, i adopted him in the end of 2016 and i feel like he's just dying from old age sadly, i hope I'm wrong and i can help him but someone please help me. I'm worried about this poor baby. he's acting very slow and as he's laying there on the wheel he's breathing a little fast, it looks like if he had the hiccups :(

Was hoping a hamster authority would get back to you with some help! Unfortunately I am ignorant on this matter, very sorry.. but wishing you and your little one the best. How's it going?