I am still quite young, but I always try to make an effort to pray 5 times a day. I really do try my best. Although sometimes I feel as though my prayer is imperfect, so repeat it over and over again till I am satisfied. Once, I prayed the Isha prayer 3 times and I still wasn't satisfied with how I performed my prayer. I also sometimes worry if my wudhu is perfect, so I also do it repeatedly. These habits are causing me to stress over my prayers, which is probably not healthy. I want praying to be something calming, not something stressful. Will my prayers still be accepted even if they are imperfect?
You are experiencing obsessive thoughts which cause you to doubt yourself. Since most likely what these thoughts are attempting to convince you of is not true, your prayers / ablution are not invalidated for choosing to ignore them. Furthermore, nobody's prayers / ablution are ever "perfect" so imperfection is all you can achieve. It is important to make the distinction between realizing you actually forgot an important aspect of the prayer / ablution and these intrusive thoughts. When a pattern for these thoughts is recognized, it is necessary to ignore them no matter how compelling they are and no matter how doubtful you've become and simply continue on with your life ( for example if you are about to pray and obsessive thoughts convince you that your ablution is invalid, you continue to pray regardless).
Ultimately, it is only Allah who will decide if an act of worship offered by a devotee of His is acceptible or not. And I know that that may seem like a no-brainer, but there is a reason I‘m leading my answer off with that Truth.
Salat has two aspects: (1) a zahiri (outward) aspect, and (2) a batini (inward) aspect.
The zahiri aspect deals with what you say with your tongue and what you do with your body leading up to and during the salat.
The batini aspect deals with what you do with your heart and mind leading up to and during the salat.
Many people tend to be rather critical of other people‘s zahiri performance of the salat. They may have a poor pronunciation of the Arabic, or their tajweed is off a little, or their back was not 100% straight during ruku, or a thousand other imperfections that onlookers may take note of and shake their heads at, thinking that Allah would surely never accept such a flawed and ugly offering.
But your Lord sees what human eyes can‘t see. He sees your batini performance of the salat. He sees that your mind is focussed on Him, and that your heart is full of love and is yearning to experience His Love, Grace, and Good Pleasure. So it‘s possible that Allah may yet see great value in a salat that human eyes may see as ugly and worthless.
That said, everyone should strive for excellence in the performance of the salat, meaning in both the zahiri and the batini aspects. The salat should be outwardly beautiful and inwardly potent (that is, done with the heart and mind fully engaged).
Excellence can only be attained through consistent and intent practice. You are on the right track in your desire to perform a “perfect” salat, but you are doing something wrong if you‘re experiencing anxiety in your practice. The salat is supposed to have the exact opposite effect on you.
Salat is a form of dhikr of Allah, (Qur‘an 20:14), and the Dhikr of Allah is supposed to make your heart tranquil and serene, (Qur‘an 13:28).
Your anxiety means you are too preoccupied (mentally distracted) worrying over the perfection of you zahiri salat. You are not performing the batini salat if your mind is tuned in to anything other than Allah and your heart is not yearning for Him. Such a salat is hollow and devoid of life and power.
There has to be a balance between correct and precise performance of the outward salat and a profound outpouring of concentration, love, and yearning directed at your Lord (which is the inward salat). Do that and all will be well.
And all it take is mindful practice.
May Allah grant to you what you seek and more. Ma‘as‘salaama.