Adjective to describe how *you* feel when something is bittersweet

Solution 1:

How about "conflicted"?

Merriam-Webster says:

: experiencing or marked by ambivalence or a conflict especially of emotions

and includes examples that match your question, like:

I'm conflicted about the prospect of our only child going away to college.

Solution 2:

I don't think "feeling" can introduce an adjective to refer to the personal feelings of "I" in that sentence, because the subject is impersonal "it" and "feeling" seems to be dangling there (that is, unless it refers to how that afternoon felt).

I can't think of an adjective, but "having mixed feelings" would be a good choice. That sentence could be recast, for example, as follows:

• It was such an intense afternoon, one of mixed feelings. I don't think I can handle another good-bye right now.