breastfeeding getting better

so now that my lo is gonna be a month ive started to try to breastfeed again and he latches sometimes, but other times he doesnt get it or want it so i have to give him milk i pumped already.

im just scared that my supply is gonna drop because right now im pumping every 3 hours getting 4-5 oz every session. but my lo eats every 3.5-4 hours. so by the time he eats my breasts are huge. and my letdown is fast so hes only at the boob for like 15 mins.

so should i continue to breastfeed him and then just pump the rest out and give him that if he wants more??