Dear Ally:
How to stop being toxic: number 1- stop fighting.
Behave respectfully toward him, practice mutual respect, and that means, no fighting, no aggression. You need to communicate something to him, to get his input? Have a peaceful conversation, a Win-Win interaction.
And so, regardless of how clingy and anxious you feel- don’t proceed to disrespectful behavior, to aggression, covert or overt.
Regarding your clinginess, possessive feelings: we can examine those, if you’d like, and if you do, consider answering this: are you afraid his friends (particularly the one you dislike strongly) will take him away from you; will turn him against you?
anita