Lee - that is an honest and open post.
Loss is so very hard, especially if it is the first one that you have experienced. We all feel for you, but, like you, we all live on - and that is what you must do too - imagine what she would say if you didn't!!
You have entered an interesting and rare space, an interlude - you say that you feel "almost disengaged/disenchanted" but Lee! That is a marvellous internal space to inhabit for Camino.
I can see that you are a Camino veteran, have done at least three Caminos - and from your "haven’t felt like doing my usual planning and plotting of distances" it is fairly certain that you are a serious planner, and if you are a planner then your habit has been to inhabit this solid 3D world more than the other that co-exists with us, that other deeper greater realm that is just as real ....
But Lee - because of the cessation of that planning and mileage mind that you feel this could be the most important and life-changing Camino you ever undertake - (I am not saying that it will be!)
- but, this one will certainly be different; if you are disengaged, disenchanted, maybe, just maybe, you will flow along without all your planning and recording of distances and in coming to terms with your loss, with your memories, with hopefully realisations of how this universe, this life, and your part in it actually really works - you just may have the most extraordinary Camino -
All I would say is to leave your mind as it is, to be not afraid .. do not over-plan this one .. just flow, stop when it is right, move when it is right, switch all your electronics off, stop writing distances into your journal and booking ahead .. be silent, speak to others, surrender to tears, drink until laughter, feel guilty the next day - but, Lee, Live.
Lee, this may be no help at the moment, maybe it will be in the future ... but .. nothing dies ... life withdraws and the vacated body dies, which is not the same. It is more like we are life itself experiencing this human life in some sort of body suit, a spacesuit if you will ... nothing dies, no one dies, they only withdraw. I have written this before and repeat it again for you - think of it as your Mum falling up out of her broken body and into the arms of angels.
Whether you are 'religious' or not is unimportant but .. maybe, on your Camino, visit every church that you can and light a candle for your mother .. pray for her, offer her to that benevolent love, and offer thanks for her in what she did for you and thanks that you, because of her, are what you are and where you are.
In essence, Lee, take this opportunity, in this slightly dissociated grief state to delve into Camino, to surrender to each and every moment, and to give thanks - because, All is Well Lee, all is well. And if you do find it too difficult, if the sorrow is too much .. the answer is utterly simple .. help others, focus to help others; look at every pilgrim you meet, the lonely, the hurt, and help them - kind word, shared meal, bathing feet, first aid, a gentle shoulder ... if you help others your sorrow will heal, it is how it is, one of the great secrets of the world.
Buen Camino Lee - and will you come back on here after your Camino and let all of us know how it went?
I hope so.