I have only a bit of experience with mead but I can offer you a little advice. Put it away somewhere and forget about it for a year or more. When I was reading up on making mead, I would see people saying all the time that meads don't really mature until after a year or more has gone by. My first mead was similar to what you are experiencing. It had a plastic flavor and very hot alcohol burn when it was young. I didn't like it at all so it ended up in a box in the basement. About a week or two ago, I thought about it and moved a bottle up to the fridge to see how it was aging. It's been a year and a half since I made it and it has really improved! It has fruity notes, no trace a plastic, and (to my surprise) its slightly carbonated even though I didn't bottle it for 6 months and the gravity had dropped to below 1.000. For what it's worth, I think you're mead has a decent chance of coming around, just give it some time.
"I'm not comfortable with home brewing, it seems fraught with mischief to me."
-UT Senate Majority Assisstant Whip Gregory Bell (2009)
"It's now legal to make moonshine."
-Andrew Adams (KSL Radio, Morning News, 2009)