When should you end a situationship?

Been in a situationship for 6 months. To start with I was just going with the flow and never wanted to pressure anything into labelling or that. However since the guy has explicitly said a relationship is off the cards my perception has changed. I can’t help but feel like I’m just being temporarily used til he finds someone he actually wants to pursue and it’s causing me a lot of anxiety and insecurity. Given this I feel like I should end things but I am very good friends with the guy and don’t want to risk losing that. Any advice? Should I do what’s best for my mental health or stop deeping it and just accept the relationship for its casual nature?
When should you end a situationship?
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