How my [20f] gf ruined my stamina in bed

Shorter past story that I’m still having happen as of tonight so it’s on my mind why it started, early into our relationship my gf began making fun of my size, being around 3 inches, so I was used to hearing about her ex being better after a few months. Eventually she wanted to make a bet with me, if I fit in the smallest cage she could get, I had to wear it as long as she decided. If I was too big, she’d let me start having sex again with her. I was confident I would at least be able to stay out of the one she showed me, as it wasn’t flat and had a little over an inch of space. After agreeing, she took my cock and applied lube, then proceeded to squish my dick into itself so tiny the cage slipped right on with little issue. She then grabbed my wrists and put my hands on her tits, so I could learn what trying to get hard would feel like from now on.

This continued everyday, the worst for me is when she would put her legs across my lap when we’d be sitting down, so they’d be on my cage making me suffer trying to grow in size. I didn’t know she was cheating at the time yet and still wasn’t her cuck so this was our sex life for months outside her sitting on my face or me wearing a strap on.

Skip ahead several months of learning to live in one and she finally decided to take it off me as a reward. I knew I was considered tiny, but having shrunk a whole inch made it even more embarrassing. The real humiliation was when she set an alarm on her phone, and decided to see how long I’d last. I wasn’t ready to learn that I couldn’t last a full minute, cumming into my condom she had me wear in around 50 seconds. This became my new standard time anytime she’d take it off me, it only going down even more when she confessed to cheating and starting to openly cuck me. Having to watch vids of her with a BBC made it impossible to last even 45 seconds, as she’d go all out to make sure I didn’t.

The one positive to finishing so fast is she doesn’t mind giving me handjob before work as it’ll be just her using 3 or 2 fingers to stroke for a minute or so. I do wonder if my stamina or size will ever return, I doubt she will let it lol