Actually, you are allowed to NOT do this. Jesus just talked, he didn't go out and looked for people, those who wanted to listen did, and those who didn't, walked by. He didn't call them out on that, either. You need to also realize that the vast majority of people you talk to in the modern world are familiar with Yeshuah's message in some form or another, we realize the claims of Christianity, we're not unaware of it. The whole thing was to spread the message to people who NEVER HEARD IT, we've heard it plenty, many of us WERE a form of Christian. We were supposed to "never go hungry again" from hearing the word, we've heard it long before you, and we desire (no, wait, scratch that, NEED) more than just the word, or bread, for that matter.
You're allowed to not talk about it, it doesn't diminish your faith to your god. Boasting (including the word) is something that your god has condemned. If you're going to fast, then fast, don't let everyone know you're "doing the right thing, and the others are wrong". Jesus may've "come with a sword", but you aren't born with one. Posting on the internet, getting in people's electronic faces isn't "love" or "helping them". You want to help someone who is LOOKING FOR HELP, so go to the suicide hotline and help people, or go to a shelter, but not the internet.