To work a 16 hour shift or to not...

My latest dilemma is my struggle in deciding whether or not to continue working a 16 hour shift once a week or stick with 8 hour shifts. Here's how it works. My job is shift work basically. There are two shifts in a day: 7am-3pm and 3pm-11pm. We work 7 days a week. When I work one 16 hour shift once a week, I get three days off in the week. When I work all 8 hour shifts, I only get two days off in a week. I know, seems silly. Most people work 5 days a week with 2 days off. One difference is they have consistency. I often work all night shifts one week and then morning shifts the next week. I work twice during a weekend every other weekend, including Sundays. This is difficult for me. I can't make plans more than a month in advance, I rarely have a weekend to have small getaways. I can't tell when the week ends and begins because it's all the same for me anymore. On that note, here are some pros and cons I have thought of for each situation.

8 Hour Shifts:
Pros-

• If something overly stressful does happen, I only have to endure the stress for 8 hours instead of 16.
• I am much more effective at doing my job when I work 8 hour shifts vs. 16 hour shifts. 

Cons-

• I have to go out there 5 days a week instead of 4.
• I am more likely to work weekend shifts. 
• It's more likely for me to work 7 or more days in a row without a day off.

16 Hour Shifts:
Pros-

• I only work 4 days a week giving me three days off.
• Once I am at my 16 hour shift, it goes by just like a regular 8 hour shift.

Cons-

• I get anxiety before I work a 16 hour shift therefore causing me to get very little sleep when I need it the most.
• I am much less effective at my job because my mindset is to just get through the day with the least amount of stress as possible.
• I get really short with the girls by the end of the night.

To be honest, the pros and cons are pretty even. Do you have any suggestions or insights? Maybe some advice for overcoming my anxiety and sleeping better?