Oversupply ? Overactive let down?

My son is 8 weeks old and we were using a nipple shield till 4/5 weeks then fed well at week 6 ... now he takes a couple tries to latch, he feeds allllllll dayyyyy long, chokes, coughs, comes off my boob multiple times?

I’m assuming overactive let down ? He’s not an unhappy or cranky baby so I don’t think it’s gas.

How did you know you had an oversupply or overactive let down?

I started block feeding yesterday but now I’m worried I’ll mess with my supply if this isn’t the issue.