我的帮助？it means my help. Thanks for my help? I think it is not right.
No, the sentence is correct. "对我的帮助” could be translated "the help for me". Therefore, the sentence literally means "thank you for the help for me" If "对” was absent, the sentence would say "thank you for my help"
Oh, now wo mingbaile! Dui is necessary. Xiexie ni!
To add to Benjamin3vald response 对我 means "for me"
Think of “大家对我” as one thought. If we put it this way, we can translate ”感谢大家对我的帮助“ to literally: "Thank you (感谢) for the help (帮助) from everyone to me (大家对我的)."
Is 帮助 plainly used as a verb? Or can it also be a stand-alone noun? (Like how you would use 合作 in 谢谢你的合作)
It can be used as a noun, which is its role here.
感谢 can mean 'be thankful', right? Then why can't I say 我感谢~?
You could, but the English would then say "I thank you".