Congrats and welcome to motherhood.
When my baby was about 3 weeks old, she was also cluster feeding like mad!
I was literally stuck with her from 6-ish pm to 9-ish pm, with less than an hour in between.
So, dont't fret. I was doing a bit of reading while I was going through this period. Was also questioning myself if I have enough milk for my baby. But since I realised that she is cluster feeding, I came to terms with it. And basically, I prepared drinks, snacks, my phone and a book and stayed in my room with baby until she is done with feeding.. So, relax and enjoy the time with your baby!
Cluster feeding lasted til she was 4 or 5 weeks old. And then she also had growth spurts.. so... not sure which is which at a certain point..
Growth spurts happens at 3 weeks, 6 weeks, 9 weeks, 3 and 6 mths.
I would say, go with the flow and feed on demand. And try not to supplement with FM, cos it will affect your milk supply... best way to establish milk supply is to latch and latch!
Before you know it, you would have reached the end of the tunnel...