en_tn/dan/07/15.md

my spirit was grieved inside of me ... the visions I saw in my mind troubled me

These two phrases describe how Daniel was feeling. The second one gives more information about the first one, explaining about his grieved spirit. (See: rc://en/ta/man/translate/figs-parallelism)

my spirit was grieved inside of me

Here "my spirit" refers to Daniel himself. AT: "I was very sad inside" (See: rc://en/ta/man/translate/figs-synecdoche)

one of them standing there

This is one of the heavenly beings who were standing before God's throne. Possible meanings 1) these are angels, spirits who serve God 2) these are people who have died and are now in heaven.

to show me

"to tell me" or "to explain to me"

these things

"the things I had seen"