If you are feeling weak...
I highly recommend you start with a cleansing diet before you begin. This will make the traditional first week blues minimal!
Big bowl of fresh fruit with natural yogurt (I like to make a smoothie)
Big salad dressed with good oil, fresh lemon juice, garlic and cayenne
All the homemade vegetarian vegetable soup you like
All the fresh fruit/veg juices you like all day, fruits am/veggies pm
If you are a heavy coffee drinker, taper off and stop--otherwise just stop
Of COURSE you can do it! And of COURSE a cleanse will bring you back up again! There is no reason you couldn't do the standard 10 days, then see how you feel, rather than setting the 21 day goal in stone--even 5 days to start, more cleansing diet, THEN on to a 10 etc...
We are here to support you! Have no fear!
Best,
Somer