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I am sorry to hear about this situation. Even if you are not part of his official family and was born out of wedlock, having an Israeli Jewish father makes one Jewish for the purposes of Right of Return. This means that one can claim Israeli citizenship based on the lineage. To begin this, one needs to contact Nefesh B Nefesh HERE. Unfortunately, there is no chapter in Nigeria but one can work with the closest one and they should put you in touch with a local representative or work with you via the internet. This organization helps individuals who fall under Right of Return to apply for Israeli citizenship and make aliyah (move to Israel).
NOTE that because your lineage is paternal, the Orthodox establishment in Israel is not going to recognize you a Jewish even if the State of Israel does. This is because the Right of Return is based on any parental lineage or Orthodox conversion, the Orthodox Jewish faith recognizes only the maternal line or Orthodox conversion.
This may create some problems down the line when it comes to marriage, for example. As such, someone in your situation may wish to formally convert via an Orthodox conversion while applying for Right of Return, or perhaps even before.
Good luck. Or how they say in Israel - b'hatzlacha.
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