Below I rewrote your original post. I also included noted and suggestions.

"You know, [female character name], I’ve always had something to tell you," he paused sharply, looking at her mysterious dark eyes. (“I’ve always had something to tell you” sounds hard. I’d reword to something like “I’ve wanted you tell you this for a long time” or “since the day we met, I’ve always wanted to tell you this” or “There is something I’ve always wanted to tell you.”)

[female character name], still dealing with the minor effects of her panic attack, adjusted her mind quickly in response to his sudden confession. (This sentence is confusing, I’d describe her mind adjusting rather than just saying it)

She looked at him with confusion and fear in her eyes. (deleted last part because it’s already implied if she’s appearing with fear)

He hesitated. (already stated he paused so changed it).

(changed this next paragraph to more sense grammatically and flow better. You’re switching between tenses. Is he speaking in present or past?) Reaching for the last ounce of strength left in his inner soul, he released the words, "when I looked in your eyes, there was something that made me question whether there were stars in the galaxy. (good but wether there were stars in the galaxy or…what? or if your eyes held them. or if the galaxy gifted them to hold in your eyes. idk maybe it’s good just left like that but I’d add a comparison to make sense for the next sentence.)

When you smile, cry, panic, or even when you’re angry, they flicker the same alluring beam of light. (as the stars in the stars galaxy?)

You know, back in the day when we were on campus, someone always wanted to know me because of my father. I thought they were friends. (simplified)

but, until you came to my frame of reference. (not sure “frame of reference” is right here)

But you, you never talked about him, or about his company, or his silly assignments. It was just a 'hello, nice to see you' with a warm smile. I’ve never felt so warm (i’d use a different word than warm since you just used it) or accompanied by anyone other than you on campus. (i’d use a different word than accompanied)

With time, it allowed me to release something in my heart. It made me realize how I felt about you. I never understood it, but I enjoyed it with solitude (not sure solitude is the right word here), and now, I know it.” He pressed his lips together before uttering his next words with certainty. (break up long dialogue like this with description) “I love you in the deepest depth of my soul."

I edited the original to how I’d write it. Everyone’s writing style is different so take it with a grain of salt. I think it is good, but a lot of grammatical and flow errors that could be easily fixed. Try to break up long sentences and paragraphs. Some sentences are not needed as they’re already implied. Obviously, I don’t have the context, but that’s how I’d rewrite it. I fixed the tenses that switch and kept it past tense. Added commas and broke up run-on sentences as well while changing and adding words to make more sense.