My contact seems super busy should I keep messaging? Introvert Struggle

Hello Monkeys! Recently one of my contacts at one of the biggest investment companies has been trying to refer me for a position. We have known each other for long and I really want to work for the bank he's working in.

I come from a non-target (very non-target I had come across lots of discrimination because of my background and I am also first generation but I never give up) so it's really hard for me to get through the door. 2

But my contact seems so busy everyday (he's at senior level) and he replied slow (but when he replies. he's still very nice to me). I wouldn't want myself to be too desperate and impolite and I also do not want to ruin this friendship but would like to keep it professional. I am wondering if he also thinks it's so little chance for me to get in but he's too afraid to tell me directly? I still think there are lots of better candidates out there with better background even I have been working this hard to get here. I do not want to send lots of messages to scare my contact because he might think I am just using him all the time. I do see him as a friend after this long, but this chance is rly my hope. What's the best ways to follow up? The time is ticking so I really need to speed up the process