3 weeks and 2 day baby

I actually have a couple of questions if you guys could help me :)

1. Is it okay my newborn seems to be eating a lot?

Insight: I’ve been bottle feeding breast milk and formula and I always give breast milk first usually at 3 oz. And if he’s still fussy 15-20 minutes later, I make him a 2 oz formula bottle. This doesn’t happen at every feeding, but often enough to scare me that I’m over feeding him? Is this the “growth spurt” or cluster feeding that I’m hearing about?

2. I’ve been seeing my supply only pump 6oz (3oz each breast) recently. I’ve tried massaging, eating lactation cookies, and pumping the times he eats.

Insight: Around Christmas time, I started pumping so my parents can have a little time with him. The more I stayed with my parents, they never woke him or me up for feedings throughout the day on time. Anyways, I’ve started seeing my supply go down and I was wondering if anyone could help me with this problem? My left breast has recently become painfully engorged today and I tried pumping it out, but I feel lumps on the top to the left side of the breast. My right breast has been pumping 2.75-3.5 oz each pump (3-4 hours). I’m using a gel heating pad right now to see if it helps but does anyone have any tips?

Thank you in advance!!