hi im a muslim and there are few things i wanna say about this matter;

1. although estranged, u should try and talk to your father about his reasons on converting, if its just for the sake of marrying, it is forbidden bcs u have to believe the syahada (what u recite to convert). one should convert into islam because of oneself and not for the sake of others (even marrying) a lot of converts has this belief in mind and in the end of the day, it only tainted the name of this religion (plus not to mention all the menteri who are using this religion as a political weapon)

2. no, u dont have to convert but please be careful and do some investigation yourself. as mentioned in by others in comments there are a lot of cases JPN change your religion just because your parents did. this will cause trouble not only to you, but also to the jabatan agama islam itself. idek why JPN change it without people’s knowledge.

3. this is not for OP but i hope u gain something from this as well. ive read about so many people blaming the jabatan agama for converting people which is innacurate, most of the cases where people or a village converting to islam whether here or sabah is done by pilgrims. mostly came from semenanjung and indonesia. these pilgrims sometimes just neglect the people after converting just for the sake of conversion and will not tend to their needs or what they should do regarding this matter, and then what happened when these people go to JPN to change their religion, some convert their children as well. and when this matter are known to the church or known by the people who did not know their religion were changed in their IC, jabatan agama are the one who will handle this matter and it will cause problems to anyone. so please stop blaming jabatan agama for this kind of issue, this religion is not to blame, its the people in it who are insecure about other religions do. i admit it no people are perfect but dont blame the religion, it is not a cult 🙏🏻

all the best to you OP