Hi Loveday, it sounds like maybe you are overtraining. Training on every day of the week is a lot, if you train every other day or vary the types of training you may see better results.
There are also lots of training tips in the Beginner Freediving section. I find the O2 and CO2 tables useful, they have helped me a lot.
When you do the open water training, have you got another freediver with you?
Lucia
