Do the two of you maybe have another mutual friend who can talk to this friend for you? Sometimes it takes another person pointing something out before someone realizes it's not just you. Or would they maybe listen to a letter/email better than a discussion? Sometimes seeing something in black and white, physical form, such as words written on a paper, helps people to have that 'Oh!' moment.
Quote by reachout.com
What you can do about a toxic friendship
None of us likes the idea of losing a friend, and some people deserve a second chance. Your friend may not be aware that their behaviour bothers you. It might be worth talking to them and establishing some healthy boundaries:</p>
<p>Say ‘no’ when your friend asks for something that makes you feel uncomfortable.
Point out to them when they’re acting mean or being critical of you.
Tell them when their behaviour is unwanted and unacceptable.
Talk to them about how their behaviour makes you feel.
It’s okay to tell them that if they aren’t willing to treat you better, then it might be best if you parted ways.
This was a good article, too: Toxic Friends: Less Friend, More Foe