From Mathew 22: 39 "The second is love your neighbor as yourself."

We see self love and from

Ephesians 5:33 Each one of you must also love his own wife as he does himself, and the wife must respect her husband.

These are important views from The Lord but as we learn from scripture

When Jesus said to love your neighbor “as yourself,” he was telling us how important it is to love your neighbor, to be genuinely concerned for one another.

Let’s look at the other verse I wrote above, In his letter to the Ephesians, Paul wrote that each husband “must love his wife as he loves himself” (Ephesians 5:33). Was Paul saying a husband can’t love his wife until he learns to love himself?
Of course not.
That would have nullified his forceful instructions to husbands to love their wives as Christ loved the church (Ephesians 5:25-32).

But do you know what else Jesus talks about?

Mathew 16:24-25 "Then Jesus said to His disciples, “If anyone wants to come after Me, let him deny himself, and take up his cross, and follow me. 25 For whoever wants to save his life will lose it. But whoever loses his life for my sake will find it.

So how does Mathew 16:24-25 relate to the two verses above?
The answer is, God wants us to have Godly love, not just for ourselves, but for one another.

So why can Self Love be harmful?
It's taking the love that God gave us to use and putting all that love to benefit ONLY ourselves when it really should be benefiting God.

The most Important detail to note is,

When we understand God’s love as a born again christian and we deeply know he loves us, we don’t need to focus on loving ourselves.

The more we experience God’s forgiveness and love, the more we think of him and the less we think about ourselves. When we are excited and secure in his love for us, we don’t need to try to find meaning by loving ourselves.

See, because we live in a fallen sinful world, we are all sinful:

Romans 5:12 "Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned."

and BECAUSE of this sin, SELF LOVE actually turns into SELFISHNESS if WE USE IT INCORRECTLY.

SELF LOVE SHOULD BE THE DESIRE TO FOLLOW GODS WORD AND BY THAT, WE LEARN TO LOVE OURSELVES THROUGH LOVING HIM.

But, if we don't love God we can never truly LOVE who we are in a Godly way but in a selfish misguided way and thats where the destruction of self love comes in.

This is why God says, "After all, no one ever hated his own body, but he feeds and cares for it, just as Christ does the church. (Ephesians 5:29)

He shows us self love is caring for ourselves as Christ cares for us.

and how does Jesus Christ care for us?

Through the Ten commandments and when we know the ten commandments and pursue them as BORN AGAIN CHRISTIANS we are doing the duty of the Lord, which in return helps us in love with ourselves, one another and the most important Love for our savior, Jesus Christ.

This is what God means by self love and if you're not born again, you won't understand this.

John 3:3 " Jesus replied, “Very truly I tell you, no one can see the kingdom of God unless they are born again."