Julie's answer is completely correct. Most English speakers can't use "whom" correctly, simply using "who" all the time. So, using "who" in all cases is very normal. For formal English, "whom" is the objective case of who. Your sentence fragment would be an adjective clause in an English sentence. In this case we can just focus on the clause. If we re-order "X I love" to "I love X" we see that "X" is the object(of the fragment), while "I" is the subject. Since "X" is the object, we use "whom". I think this page is helpful: https://www.englishpage.com/minitutorials/who_whom.html

Both of these make sense. “Whom I love” is more formal and “Who I love” is more casual/more accepted than using whom.