What should I do with the clingyness of him?

Well, me & my boyfriend have some.. issues.. When I walk to my friends house he follows me some times & I don't notice it.. Last time I left the house while he was asleep & he called me yelling "WHAT THE HELL, ARE YOU CHEATING ON ME, YOU DAMN MAN . WHERE ARE YOU?!" & I some times cry to myself as he does these things.. Today I was on the phone with my bestfriend Becky & he was behind me listening to our conversation.. then after I got off the phone I see him with a big grin on his face asking "Are you going straight on me, stupid boy, your never leaving me.. if you do.. you won't find any one better & I have to admit, neither will I.." & he grabbed my bum & walked away. Some times he even holds on my hand in the car with friends. It's actually kind of .. scary. What should I do? By the way, we both love each other very much.