There are two ways to practice magick -- your own mind and will alone or help of other forces, powers, or spirits. The second comes in the form of symbolism, sigils/seals, names, representations, invocation, evocation, etc. The first generally uses either pure energy manipulation, trance work or sympathetic magick. Most people do both.
Honestly, the words are nice but are less necessary than the actual plan, which is lacking.
Have you ever seen one of those marble mazes, where you build a little roller coaster and drop the marble at the top and watch it fly down all the loops and trap doors? If you just drop the marble without the cool little contraption, your marble will still meet the floor. But there isn't very much control. Which direction it rolls is questionable. Well, your will/focus and the forces/powers/spirits you utilize are the marbles. The ritual you build is the way you choose to direct it.
Your form of writing spells is about as focused as dropping a bag of marbles and hoping one shoots off in the right direction. You don't even specify which spirits are helping you. Any spirit could just walk up and do whatever. That's scary.
Words are weak. They're pretty but they're empty without connection to something. "Words of Power" or "Names of Power" are some ways to add direction to words because they are already connected to something. Rune names are a great example of the indepth meaning behind a single utterance. But even then, the word in itself is nothing without more direction. Your intent, passion and will.
Words alone help you to focus. They are merely something for your mouth to do, your mind to imagine, your ears to hear, and your emotions to fill. It is a way to make your voice an instrument of your will. Sound becomes the way the spell is carried into this world. But if all you are focusing on are those words, nothing much will come of it. You need more.
Magick isn't about shoving as much energy into something as possible. It isn't one size fits all, and all you have to do is change the wording. You need more depth, whether that depth is the understanding of what you are approaching and the solution (through visualization or energy manipulation) or whether it is gaining the aid of a compatible "spirit of ____" that will do that for you. This is why symbolism is used. It also holds connection. This is why witch and mage come from words meaning wise.
If you want that marble to get build speed, you need to understand physics and what can create the increase in velocity. If you want that marble to spin, you need the right components. The metaphor can go on and on. You get the picture.
Back to words.
Words in the form of poetry is meant to create a rhythm that puts you into a trance, much like a drum beat. Another way poetry can be utilized successfully in magick is like the bards of old--to sway the hearts and minds of the ones (spirits) listening. Or it could be used to praise these spirits in song. Because who doesn't like having a song dedicated to them?
Words in the form of mantras are also used for trance, but the best ones contain words of power with deep symbolism that is supposed to be reflected upon as it is sung upwards of hundreds of times.
As for your pain, I would seek out "spirits of" that specifically deal in healing. I would also focus on healing the cause and not just taking the pain. Pain is an indication of injury. It is also a product of tension and inflammation. In a spiritual perspective it is trapped, ill, or stagnant energy. You are asking them to take the pain, which is a nice idea but not very possible. To heal pain one must free up the blocks or cure the cause. You say you choose things that are possible, yet jump straight for a wish instead of looking at the bigger picture. That's like taking a pain pill instead of setting a broken leg. I am a firm believer in healing through magick.
No, you can't grow wings but healing? Healing is something our body strives to do constantly. It is forever rebuilding itself. So it is in fact within natural laws to do so. Sometimes our body actually heals itself too much and causes problems that way. I definitely feel wellness through magick has an excellent chance of improving the quality of life. It is not a substitute for physical care because we ourselves are both beings of both physical and spiritual sides. But sometimes the spirit is the side that makes the difference and it is consistently the side that is commonly ignored.
Try this instead.
1. Desiring what I want with clear direction and concentrated focus. Map out what the problem/situation is, how I desire to meet my goal, and the results. The results should be spoken with conviction. It will be done. No exceptions. Lack of conviction creates a weaker willpower.
2. No specific # of lines nor a need to rhyme. Even one solid word works. Or no words. But imagery and wording matters if they are used. Double meanings can create loopholes. The instructions must be air tight.
3. Draw energy from within and from within the source that ties us all. Pull it up from existence from you. You become the catalyst. You become the bridge. Bring that energy into manifestation through one's self.
4. Cast it by chanting over and over, building emotion and power within through every repetition until it is coursing through one's self and ones sacred space. Then if you wish you may " burn it in an old pan to seal it, cool ashes with water to quench it, absorb excess moisture with dirt to nourish it and scatter the rest to the wind to carry it."
5. Thank the spirits that aid you