Did you both make a to each other? There are many reasons that make it hard to break up with someone, but if you think there are still lots of positive reasons, and your partner is willing, you should try to give it another shot, then do your best to try one last time.
You feel drained and exhausted like you have nothing left to give.
If you find yourself constantly giving everything for your partner without the gesture being reciprocated, it can create a power imbalance that breeds long-term unhappiness and resentment.
If that was being selfish, than I would be selfish.
If your significant other has a history of lying or cheating, this causes a buildup of resentment that can quickly poison your relationship over time.
"I have not been feeling fully satisfied in this relationship and think it would be best if we broke up.