Sister Relationship

I live with my sister and her boyfriend. I love them both so much but sometimes I feel like because of my past experiences with my sister growing up I have a hard time completely trusting her and having the relationship I want with her. I’ve done the model and understand how my thoughts about her can change, but how can I change this thought when she is consistently proving my other thought? I try and have a complete transparent relationship with her but she constantly throws what I share with her as a way to put me down in front of her bf and just with me. I stop sharing things with her and she tells me I’m “closed off” and that I don’t have feelings. Obviously I know this isn’t true and this is just her thought about me which is out of my control. But would it be useful for me to tell her why I don’t share things with her? I want a stronger relationship and to share things with her but how can I do so when this is a constant issue. Appreciate any help or insight!

Models Below:

C: Sister
T: I can’t trust her with my personal feelings because she uses them against me/or puts me down
F: Untrusting
A: I withhold feelings
R: She calls me closed off and weakens our relationship

C: Sister
T: She loves me and has my best interest at heart
F: Trust
A: I confide and open up to her
R: She uses these things to put me down

Both results are counter productive for our relationship, so I’m really stuck with what to do.