Should I break up a two year relationship over the phone?

I was thinking of breaking up over the phone by text messaging, But maybe it is wrong and I should talk with him personally and work things out, he is older than me he is actually in his mid 30s and I’m in my late 20s, the reason is that this relationship makes me weak and I’m afraid it will end in the long run.I want to be happy and I don’t feel happy, its not all because of him or the relationship itself but also for some personal things and I truly feel overwhelmed.