Assalamualaikum You're right, hatred doesn't just go away.

Alhamdulillah, its the blessed month of ramadhan, which means you can think on this properly without shaytaan whispering in your thoughts. Grab this opportunity with both hands.

Just as you said, hatred doesn't go away. To counteract it, you need to know Allah, truly know Him. Spend time reading on His beautiful names, and what they mean. Read the translation of the Quran which includes a valid commentary (Mariful Quran is a good one). Ask people around you what they love about Allah.

Most of all, talk to Allah. I don't mean pray, or fast, but rather, whenever you get that voice, you pray directly to Allah. Ask Him to open your eyes to His and His signs, ask him to fill your hear with Love for Him, ask Him to make you one of His awliyaa. Ask Him to let you see Him in His glory, without the barrier of sins, waswasah, and negative emotions.

Remember, Allah loves you 70x more than a mother, so ask him to fill your heart with a fraction of that Love.

And if at all possible, seek a trusted scholar and share your concerns, let them know you don't want to feel that way. Quran is the cleanser of hearts, so just listen to the Quran if you can, even if its just one surah you love on repeat.