"If this isn't love, then why does it feel so good?"
What is love? Is it a feeling? Is it attraction? Is it an action?
For me, Love is (quite literally) my God. Love is the only thing that means anything. Love is an imperishable and inexhaustible force. Love is the sum of actions in self-denial. Love is a choice.
You don't fall in love, you choose to love someone. Love doesn't fade, you choose to withold your love. When you /enjoy/ someone, you are enphatuated or attracted to them. When you return anger with patience, pain with understanding and betrayals with forgiveness, that is Love.
When you tell someone "follow your heart!" And watch as they are destroyed by a toxic relationship and you wave the "follow your heart" flag and the "do what makes you happy" foam finger at them. That is not love. Telling them "hey, i see these things happening, you arent alone, you deserve Love." Is love.
Choosing to stay with a toxic person because "i love them!" Is not love. You hitch yourself to a burning ship out at sea and allow them to destroy themselves while dragging you to the depths with them. Telling someone honestly "i can't be one with you while you are burning, but i will not abandon you while you put out the fires" is love.
Being so afraid of your loved one betraying you that you are always suspicious and afford them no freedom... that is not love, it is selfishness.
Trusting your partner and accepting that they will one day betray and hurt you while allowing them all the trust and freedom they should have... then, pre-deciding how to forgive them... that is love.
"You pick the flowers you like, you nurture the ones you love."