Failed Open Water in Dry Suit and Devastated - Any Advice?

[GiraffeMarineSalvage]

It's a bummer to hear of a beginner course that flies through everything too quickly to effectively teach (let alone make sure critical details like your neck seal wasn't too tight, your weighting was roughly correct, etc, etc) and then leaves a student full of self-doubt. Don't be too hard on yourself...
Warm water diving is dramatically easier than coldwater diving, and there are TONS of people that choose to only do warm water diving for a reason (I even once got a free dive tank because a coldwater diver local to me decided moving forward they would only be diving warm water...)
It's also worth considering simply working on physical fitness and finding a local dive instructor focused on a their students and having a logical stepwise progression (and using 7mil wetsuit then dry suit as an additional course would be reasonable, but not inherently necessary depending on your comfort level..) as a viable option.

 

[iceman4160]

I agree with comnent about working out you don't have to hit heavy weights or run a marathon. The idea is to get stronger and get fit. I'm 6'1 and weigh 207 lbs, when I retired I started working out for two reasons 1. To stay in shape and 2. To get stronger and in shape for my OW certification, I did my OW certification in 42 degree water wearing a 7mm full suit with a 7mm hood , boots and gloves.