Ok, well I just wanted to add my very similar experience with the "rental wetsuit" here for posterity. Gosh, how humiliating!
I went to the LDS to do what I thought was just get my stuff for my checkout dives, at least that's what the instructor told me. I knew I'd have to try on the wetsuit (since the one I ordered hasn't arrived yet and I don't know if it will in time) but he didn't tell me to wear my swimsuit and he didn't tell me I'd actually be getting in the water with it. Maybe I should have known that trying one on automatically meant swimsuit but I figured I could do it in my bra/underwear. So needless to say that started out on the wrong foot.
Then he was determined to fit me in a ladies size wetsuit. I've posted on here elsewhere my stature... I'm a big girl, I'm not ashamed and I'm not trying to hide it so why should anyone else? Put me in a man's suit, I don't care as long as it fits! So THREE attempts later I finally ended up with something that kind of fit (the crotch was still droopy but by that time I was too tired to pull anymore). I was sweating so hard I thought I was going to pass out. The first two (these are 7mm farmer john's so pants first, overcoat second) I couldn't even get on past my calves. My calves are big. Really big. I never got the first suit past my calves.
I got the second suit on up to my butt, then realized that I had stepped through the arm wrong and couldn't pull it up any further. I gave up on that one too out of frustration. Peel it off, clothes back on, outside to get yet another bigger size. I finally got that one on well enough that I could walk out like a penguin. So humiliating.
Then to continue the humiliation I got to put the hood on, then do the weight check. He says "we'll start with 24lbs". That's the 10% rule for me. Lay down in the water, let the air out of the BC, roll on my back like a seal. Add 8 more lbs. Retry. Roll over on my back like a seal. 4 more lbs (for those not counting, we're at 36 now). I stopped rolling over but still couldn't sink. I think he gave up and just said "well, that should be close" because he couldn't believe I'd need even MORE weight than that. Hell, neither could I but trust me, I was floating like crazy. I'm *going* to need more lead. Further humiliation.
I was still sweating like a pig because I'm in my 7mm farmer john in a pool that's 85 degrees after just having spent the last half hour trying to struggle into these things that were too small. He finally gave me a break and said "ok, you can get out of that now". Since I hadn't come prepared to get wet I got out of the suit, dryed off with some paper towels, stuffed my wet underwear into my sock and into the back of my shorts and tried to keep my head up while I went back out to meet with him and get everything wrapped up.
Dear God that experience was almost enough to make me say "forget it, I'll do my checkouts by referral on vacation". At least that way I wouldn't have had to endure all this torture! Sheesh!! I sure hope my Henderson Hyperstretch gets here tomorrow and that it's easier to deal with than that darn rental suit!!