Why should anything stop you from enjoying yourself? Have your own set of cheat days, convince your mind and splurge at times on some wine or any other drink, just make sure your cocktails don’t have anything raw in it (just one glass on your good day), permission from your doctor is mandated for sure, and try and make sure you have plenty of protein intake. You can replace lentil with chicken for a better source of protein.
A little note for vegetarians -
My mom was a pure vegetarian, but her doctor recommended meat (mutton & beef too, she stopped at mutton) as the best source of protein so she would have meat broths whenever possible and even enjoyed it on most days.
Keeping yourself hydrated becomes essential, because you might not have the stomach to eat too much, but water is necessary. Chemo can drive out every ounce of energy in you, when the chemicals play their role. Flush it all out, and feel as fresh and new as you can, bottled water is a very good source of doing so. Soothe the body with some tender coconut and maybe some wheat grass juice, they are both rich in vitamins. Something that worked well for my mom was having a bottle of fresh tender coconut water in the fridge every day. It was effortless to organise and made a world of difference. Just remember the tender coconut water is opened at home, and never at the vendor as it isn’t very hygienic.
There are some vendors who grow wheat grass in safe and sanitised ways for those undergoing treatment. Wheatgrass is ideally to be grown at home, so it can be cleaned thoroughly. Fresh orange and sweet lime juice are also great sources to hydrate. You do not need to miss out on some of life’s essentials like coffee or tea, obviously best when hot and made fresh.
During your treatment, some juices you may have enjoyed before may not suit your palate anymore, pomegranate juice just didn't work for my mom at all. Don’t get discouraged with this, try other juices that could work well for you but make sure it is all prepared at home – fresh fruits that have been washed and peeled thoroughly!