Did I (24M) act coldly with my girlfriend (24F)?

My girlfriend and I are pursuing MBA and live in a co-ed hostel. We were both in the mood for sex, but I backed out due to body pain, which upset her slightly because I had sort of initiated the entire thing. I profusely apologised and tried to make her realize I wasn't physically in the right state for intimacy. She still seemed a little upset, but let me sleep in my room since we both have single beds and I needed more space to rest. She seemed fine with it, but a few hours later, while I was asleep, she came to my room and woke me up to sleep together. I responded grumpily, didn’t appreciate her affection, and reluctantly invited her to sleep with me. She was upset but complied. Later, sensing tension between us, I cuddled and hugged her in my sleep. The next morning, she accused me of being cold.

Am I wrong here?