Too late?

I know reading posts on this forum makes you feel like you wasted all your life. But not everyone had the guidance or exposure growing up to explore different subjects and it is okay to discover it a bit late.

I personally discovered IB less than a year ago as a Masters student with no prior finance experience. But, I am still trying my best. Because not securing it is better than just not trying at all.

I almost had an in by getting a private equity internship in New York but then due to visa timelines in the US, they went with the second candidate. So I am continuing again from scratch.

My advice to you is don't quit. Reach out to people. If you have true interest, bankers will see and acknowledge it. You might have a higher probability by reaching out to people at a MM bank, but also try the BBs and EBs.  
It will feel like you are failing a lot, but remember it only takes one person/place to believe in you. 

Lastly, I don't know what you mean by private equity research because PE and ER are two different things. For ER in general, there are firms like Jefferies who even have career shift programs for people with 2-5 years experience to pivot to equity research.

So there are always possibilities. But the only way to ensure failure is to never try at all.