Condoms too small

My boyfriend and i have tried over 5 different types of condoms (yes even magnums which are total bullshit 🙄) and we cant find any that are big enough. Natural lamb Trojan condoms are the only ones that dont choke the base of his dick. Every other kind we try have a base that is too tight, which cuts off the blood flow- causing him to go soft. The lamb skin ones are almost $9 for a box of three condoms. Does anyone have a suggestion for bigger-based condoms that aren’t expensive or where we can get the Natural Lamb ones for less $? This is basically a cry for help 😫