Hello! I just decided to go hog wild on the work of a total stranger. I hope you don't find me too presumptuous. In fact, I'm sorry in advance.

It was as if I was a waking up from a dream.

Maybe not imagery, but right off the block you have done yourself a disservice with a very wordy and unnecessary turn of phrase while violating a cardinal rule of showing and not telling. The ensuing imagery is there to do exactly that! I can see you're trying to construct a perfect opening line, but you are better served by jumping into you description.

When the sunlight grazed my skin and seeped into my vision, all the fatigue and worry that had accumulated within me fled from (through?) some splintered crack in my soul.

Boom. Your treatment of the sunlight is money. Just trim the unnecessary bits. Consider the second half of your imagery- is this anxiety a snake slithering through a hole in the boards of a shack? Is it a lake draining away? You're passing up an opportunity there.

But it wasn’t happiness. It was this feeling of... supreme serenity that overtook me and embraced me(choose one verb and invest in your chosen metaphor) as if we had known one another for years a hundredfold.(super wordy and melodramatic)

I can see you like ellipses. So do I! However, this one really broke the immersion you were building with your literary style imagery. It shifts the focus to conversational rhythm rather than building your image.

The light, the warmth (conversational) that surrounded me gave me an awareness of the world that I didn’t think I would ever reach.

The golden rays shot from cracks in the clouds like water seeping(too much seeping here) through a poorly-structured roof, and dripped onto the world.

The ocean? The forest? You set up this image and then we don't get to watch the sunshine drip onto anything, just "the world". Where are we? This is the time to get detailed and transport your reader to a setting. Where do you see yourself?

The watercolor spread and seeped(find another word) into the trees and hills. Seeing a master at work for the first time… it's… enchanting.

Show us that it's enchanting. Don't tell us how we feel as we step into your shoes, make us feel that way. Also ellipses are not your friend here.

I could have sat there for hours and not have known it. Just drifting into the world that was being made before my eyes. Each brush stroke brought new colors, and, along with them, feelings that I would have never been able to extract from such simple paint.

Nice. This flows much better and you aren't stuck in the mire of "like" and "as if". I almost feel like you could start off with this.