וַיִּירָ֧א יַעֲקֹ֛ב מְאֹ֖ד וַיֵּ֣צֶר ל֑וֹ וַיַּ֜חַץ אֶת־הָעָ֣ם אֲשֶׁר־אִתּ֗וֹ וְאֶת־הַצֹּ֧אן וְאֶת־הַבָּקָ֛ר וְהַגְּמַלִּ֖ים לִשְׁנֵ֥י מַחֲנֽוֹת׃
And Yaakov was greatly afraid and he was distressed; and he divided the people that were with him, and the flocks and the cattle and the camels, into two camps.
Torah Temimah points to Bereshit Rabbah 76:2 (and parallel discussions).
Sefaria · Bereshit Rabbah 76:2
וַיִּירָא יַעֲקֹב מְאֹד וַיֵּצֶר לוֹ. רַבִּי יְהוּדָה בַּר אִילְעַאי אָמַר: אֵין יִרְאָה וְצָרָה אֶחָד? אֶלָּא וַיִּירָא שֶׁמָּא יֵהָרֵג, וַיֵּצֶר לוֹ שֶׁמָּא יַהֲרֹג.
“And Yaakov was greatly afraid and he was distressed.” Rabbi Yehudah bar Ilai said: Are fear and distress the same? Rather, he was afraid lest he be killed, and he was distressed lest he kill.
The Midrash distinguishes the two verbs: physical fear of death versus moral distress at the prospect of having to take a life.
Derash on the double language (Bereshit Rabbah) — distinguishing fear from distress.
Yaakov feared for his own life and was distressed at the possibility that he might have to kill another.