You feel lonely even inside your relationship

Loneliness beside the very person meant to cure it is one of love's sharpest griefs, and I will not tell you to be grateful you have a partner. Loneliness inside love is a particular, sharp grief — lonelier in some ways than being alone, for having a partner is not the same as being truly met by them, so this is real and painful, not ingratitude; do not dismiss it because you are technically not alone. The loneliness points to a lost connection, not a lost love — it usually signals that the real meeting and being-known has faded into parallel lives side by side, so the remedy is to rebuild the lost connection, the deep talking and meeting of inner worlds, rather than to conclude the love has failed. And reach across the distance, and ask them to reach back — turn toward them with real openness and invite the deep meeting, telling them you feel lonely even together, for the lonely distance rarely closes while both wait for the other to cross it first. What's missing between you that makes you lonely?