I mean supportive in the sense of "giving help or assistance". Unsupportive denotes a lack of aid, but I'm looking for a word that expresses the opposite of support. This word would be used to describe someone who is impeding my efforts or hindering me in some way. Ideally, this word would not imply villainous behavior, just perhaps working at cross purposes.
I might use it to say, "Not only are you not being supportive, you are being ...." or "Can we work together on this? As it is, your ... actions upset me."