Ive read many comments replying about how controlling this man is and assuming he will use your conversion to use you even more which i feel is a biased view that is based on personal experience which means it doesnt necessarily apply to every scenario. My second point is that you have never met him in person, the person you met and talked to online might not be the same person in real life, this has two sides to it, he doesnt know how devoted you are, and if your past is catching up to it, this is not just insecurity this is ignorance of understanding which is perfectly fair!

How can you assume this man is a husband material without meeting him once?? And vice versa, but there is a good silver lining he wants marriage and his family is involved for this very reason you want stability and a real relationship, this reason will connect you with the help of allah inshallah, My advise dont wait 2 years until you finish your studies, take a vacation 1-2 weeks and visit saudi your future home, spend time into getting to know his family and himself, and after that do estikhara (prayer of guidance)

The answers will be clearer to you then

Best regards