hey,
there is something your eating that could be causing you to stall and knocked you out of ketosis. if your never testing positive you are most likely not burning fat. it could also be your water intake if it is a lot, but you should atleast have a lightest pink at some time or another.

try backing off the food you are having that you think might be hindering you. you can post what you eat here and im sure we can help you.

i test every morning and mine is always dark purple, but as i drink my water through the day it is light pink to negative. even if it is the lightest pink you are in ketosis.

it is normal to feel weak. your body has to adjust to burning fat for fuel instead of carbs. you should be taking a multivitamin and some type of fish oil a day.

hope this helps.