I have a long way to go with my swimming techniques, should I keep going with the program even though I'm not able to complete the swimming portion of the workouts?
Absolutely, if swimming is your weak area then you should definitely work on it more. My private facebook group for clients is a really great resource for help too. There is a lot of great swimming advice on there. You could read the book Total Immersion or even hire a swim coach. It's just important to try and get all the distances in. I would even recommend if the swimming is what you struggle with that you spend even more time in the pool and gaining that confidence, water is a crucial part of being a PJ.
Are there any specific swim workouts for someone who is 5’8” or below?
Something that really helped me get faster in the water was using a kick board and alternating with hand paddles. It helps to really strengthen your stroke/kick.
I'm having a really hard time with the swimming, I was wondering if there was anything I can do to make it better?
Find someone who is good at swimming and ask them to teach you, or hire a coach. Swimming is all about technique. Total immersion is a great resource.
What is a good pool substitute workout?
You can’t really replicate pool workouts, but I would use a row machine or the versa climber/Jacobs ladder. Just something that is low impact and uses upper and lower body.