Hatred or hate is an emotion. Hatred could invoke feelings of animosity, anger, or resentment, which can be directed against certain individuals, groups, entities, objects, behaviors, concepts, or ideas.Hatred is often associated with feelings of anger, disgust and a disposition towards the source of hostility.
You have the choice to convert in secret, or to convert and tell them.
What is best to do really depends on your situation and on your relationship with your parents. If you have a close relationship, and they would be hurt if you don't tell them, or if they found out by accident, it might be good to tell them sooner rather than later. If you think it would just cause problems for yourself, needlessly hurt them, or endanger you (for instance, put you at risk of being kicked out), then maybe it is better to wait.
If you think you will be living a more independent life soon (for instance, living on campus at a university, or working and living on your own), it might not hurt to wait and tell them when you have more control over your life.
However, eventually you will (probably) have to deal with it. Although it might cause conflict and tension in the beginning, the best-case scenario to hope for is that it could eventually lead to mutual understanding. The real question here is when to go through that, and that is something you have to decide for yourself.
Also, keep in mind that it is difficult to keep secrets, and people often sense what we are hiding or find out accidentally.
It is not permissible to hate your parents and deal with them badly
even if they are very bad persons. Allah The Glorious said in the Holy
Qur’an : But if they (your parents) try to make a polytheist (Mushrik)
then you do not obey them but behave with them in this world kindly
(Surah Luqman ; Verse 15). So even if the parents are so bad and try
to make you a Mushrik which is the most dangerous major sin, you
should not obey them but you must continue dealing with them nicely.
The parents who do bad, need more Dua (supplications) from their
children to be guided to the right path.
If the parents insult Allah (SWT) or the Holy Prophet (SAWA) you should not join them at all while they do that.
If the parents don’t give you your rights that does not mean that you forget their rights on you as your parents.
Their sinful acts will be on them and you must fulfill your
responsibility in being always kind and good to them.
As Muslims we must always be forebearing and forgiving, even to those who wrong us. The holy Quran clearly tells us that we must not hold grudges against those who believe. This is in verse 10 of Surah al-Hashr:
And do not put in our hearts any rancour towards those who believe.
Regarding someone being family and kin, we know how Islam emphasises on observing the best of conduct regarding one's family. There will always be disputes and disagreements, but a believer must never harbour any resentment towards another believer.
What we can say is we leave what they did for Allah ta'ala to deal with.
With prayers for your success.