I want to start with this, but I don't want to blame him, I was provoked to shave my "uni brow" by my older brother as he teased me about at, so I did. I did not know it was haram at the time, and now realise it is a major sin. I hate my eye brows now but I also hate how I performed a major sin, how can I get forgiveness. Praying? What duah do I say? Thank you for your time.
The middle part where the hairs meet,'uni-brow,' is not part of the actual eyebrows and can be removed. The Quran permits the removal of all kinds of hair and does not say it is haraam.
Even the Saudi-Salafi scholars allow plucking of the uni-brow as mentioned:
Question: What is the ruling on plucking the hair between the eyebrows?
Answer: It is permissible to pluck it, because it is not part of the eyebrows.
You should be extremely careful about making things haraam, as this can be a form of Shirk.
In the name if Allah, the Most Gracious, the Most Merciful,
It is haram and prohibited to pluck/shave/cut the eyebrows as it is considered changing Allah's creation. This is taken from the hadeeth which is narrated by Al Bukhari in his saheeh (4886) and by Muslim in his saheeh (2125):
Ibn Masoud (RA) said: The Prophet (Sallallahu Alaihi wa Sallam) of Allah cursed those ladies who practice tattooing, those who get tattooed, those who cut the hair of their eyebrows, those who have their eyebrows hair cut and those who make up gaps between their teeth to get more beautiful changing thereupon the creation of Allah.
However, what you did my brother (from what you wrote, i understood that you cut the part between your eyebrows only) isn't considered as cutting the eyebrows!The area between the eyebrows is not considered a part from the eyebrows, so there is no bad deed in cutting it! Just make sure you don't remove anything from the actual eyebrows.
And Allah knows best.
Refer to this for more details.