I understand how you are feeling and only you and you alone will know when it is time to give up and move on. As much as everyone would love you to continue working on your M you are the one living your life no one else.
DBing is not easy on us, it is hard work. It is normal to feel that everything is too much Nell and things do get on our nerves and we feel overwhelmed from time to time because we are the ones carrying the burden of everything that needs to be done.
I don't have an answer for you Nell other than to let you know I know how you feel and can sympathise with you wholeheartedly I have been where you are now and I am sure I will be back there at some point further down the track.