Dear Confused Girl,
Well, you know it’s always going to start off rough when the first word is “well,” and this is no different. Your friend doesn’t seem to be a friend at all. Her behavior has been manipulative, controlling, and showed you no respect for boundaries.
I know it’s difficult to let go of what’s familiar, especially after investing three years of your time, energy, effort, and emotions into this relationship, but the truth is, she has proven that her needs matter more than yours. A real friend would want your happiness with or without them.
With recommend you end this toxic relationship before you, her, him, or all three of you end up emotionally drained and damaged.