Psalm 139 says (in a very paraphrased way) that God knows you. He is well aware of all of your thoughts. He tucks you into your future and even into your past. He created you with purpose even while in your mother’s womb. It says to praise him, for this creation of his (you, us) was wonderfully designed. It’s beautiful in the most profound sense of the word. Made for eternal good things and strengthened for the opposition of evil, humble yourself before a powerful, loving God and continue the journey toward his purposes.

Because the eternal creator created you, you have infinite worth.

Because you were created in the image of the eternal creator, you were designed with eternal purpose.

Because God created you, that is not confined to time; he knows your days and still holds you in his hand. 

I once heard a phrase in passing that stuck out like a sore thumb. "Design reveals the designer's will." In my younger Christian days, I thought I had to wait for a gift to randomly come from the sky before I understood what I was called to do. Now that I know the Word better, I see how God called Abraham ("Just start going, I'll tell you where later"), Bezalel ("I've gifted you with craftsmanship, and you will now train others to build the tabernacle"), and David ("your skills shepherding will be used in your kingdom calling").

Yes, of course, God can and will use people; however, his spirit wills (1 Cor. 12:11). But what I'm saying here is that God has also designed us generally in the imago dei (Gen. 1:26-27) and individually (as seen in Psalm 139). Therefore, your design, value, and giftedness are designed in the womb and shaped throughout life. Then, when you become a regenerate, practicing believer, you become redeemed (2 Cor 5:17), and your gift that God has given (1 Pet 4:10; Eph 2:10) gets enriched (1 Cor 1:5). This clear picture of being made in the image of God is the foundation of our identity.

Meditating on this Psalm (and all of God's Word, for that matter) will help you find your identity as a redeemed child of God with eternal value. Nothing else is worthy of giving you your worth and calling flowers from that root.