Establishing schedule with BFing and Expressing

Hi all

My baby is nine days today. Initially I wanted to just BF him, but we struggled with the latch. This led to baby losing significant weight and being readmitted to hospital and put on feeding schedule (expressing every three hours).

Now we are home we are doing a mixture of breast feeding (with help from nipple sheilds) and expressing. Baby is gaining weight and doing well.

I have a few concerns though...
I try and express every six hours for fifteen minute sessions (using Mandela swing pump) and breast feed between. Occasionally I miss a feed/pump as my partner gives baby the bottle so I can sleep. Will this method help to establish a steady milk supply? At the moment I have a very heavy supply and often drench breast pads and give baby a milk shower when feeding... I'd really like this to calm down!

Am I susceptible to mastitis/blocked ducts? Especially as I have a very large milk supply and am intermittently feeding/pumping without a steady routine.

If anyone has any tips or advice on how to make BFing combined with expressing workable I'd really appreciate it. I feel like it's going okay so far but not sure if I should have more of a strict routine for pumping/feeding.

Thanks in advance!