Help me please pleeeeeeezzzz?

okay im a 8th grader and theres this guy that i like or i tink i do...he liked me last year but now hes changed like i wanna be friends with him but every 2 weeks we switch off. like were friends for 2 weeks and 2 weeks later hes not my friend,he gets mad at me..i told my friend this and she told me to ask him if were friends or not..but im scared ...should i go up to him or on fb or should i wait... TELL ME PLZZZ