I think if you are struggling too much.... You are going to eventually damage the suit, and break the seams. I would say, invest in a newer suit with better elastic property. Folks complains that hyperstretch material compressed too much at depth, and not as warm.... But neither is a cheap rigid wetsuit that doesn't comform well to your body, and let that blast of cold water squish in the spine area of your back. My sister bought her daughter a cheap wetsuit.... I kept on saying - "its too tight". She said, "it will stretch and fit". Within 3 dives, the seams start coming off at the butt... The tightness would've been worse in cold climate.
I've seen "generic" brands of moderate stretchy wetsuit through diver direct, I believe, for about $100. New henderson hyperstretch can be had too, check out ebay. I bought a 4 brand new henderson hyperstrech suits off ebay and scuba.com for about 1/3 or 1/4 of new price. I dive very cold water with my full hyperstretch and a corewarmer .... and few very little if any water movement within the suit. Can't say that with any other suits - as water tends to slush in the back - and you can feel that cold water really really quick. As I see it, the less water movement, the more dry you are, the warmer you are. My hyperstretch hood keeps my hair as dry as a drysuit hood, and much easier to put on.