Catra engages her feelings all the time, just to her detriment. At several points you can see her coming to wrong conclusions about her emotions. Promise highlights this as you can pretty directly see her coming to increasingly faulty conclusions about her feelings towards Adora and her own aspirations. She determines her affection was misguided and that ultimately her relationship with adora was toxic, how her feelings of vulnerability were weakness, turning to her feelings of jealousy and betrayal instead. You even see her doing the crazy people eyes as she tries to logically explain to herself and and Adora why she's trying to kill her right now.
She then spends like three seasons exacting petty revenge on Adora, showing increasing degrees of malice. Her first major collapse comes from trying to engage with her feelings on Shadow Weaver and getting betrayed, again, to which she eventually responded to by trying to destroy the world. Even in season 4 you see how unclear and confused her feelings are as she talks to (a long since left) Scorpia about how she thought indulging in the war effort would make her feel good. She even tries reaching out to the BLT squad during her last psychotic episode, but after having been burned like three times already she immediately pulls back and resorts to anger.
Catra works on impulse and engages whatever she feels at the time, she just lives in a literal evil empire and negativity is the only thing consistently rewarded, so she trains herself to only really indulge in that. She lies about how she feels to people, but she actually believes the lies, which only confuse and frustrate her further.
And how fucked up she is as a child in the season 5 flashbacks makes me think she was probably crazy the entire time. I mean it's no secret she's modeled after people with BPD. I can really only see her actually determining she's in love with Adora by season 5, before that her head is just too full of fuck.