There are many sounds that do not exist in Japanese, also basically kana is a combination of consonant and vowel. So when you're writing foreign words in kana, you should pick up the ones that sound close to the original language.
V is usually written as ヴ, and R as ル. ディ or ジ is more commonly used than ヂ.
So your name is written
ヴラディミル or ヴラジミル
司 is a nice choice for a name, though combination of three kanji is rather odd. As a name, 司 is pronounced "tsukasa" on its own, but when combined with other kanji, it is usually pronounced "shi" or "ji".
I think that taking one of 平和 and add 司 would make it look more like a name in Japanese.
平司 Heiji, or Heishi
和司 Kazushi
(To me the latter sounds natural as a name in Japanese.)
助け is only a part of conjugation or noun.
Imperative for 助ける is 助けて.
助けて! Help me!
助けてください。 Please help me.
(Just a side note: when asking for a hand rather than asking to be getting out of the crisis etc., 手伝う would be better, like 手伝ってください. It really depends on the context.)