Hi Francesca,
Have you asked yourself WHAT it was that brought back memories of a past lover? Why your relationship didn't flourish into something permanent in the first place?
Transiting Saturn conjoined your Cancer stellium before it reached the Saturn/Pluto conjunction. I'd suspect that it brought about a series of endings with, and retrospection towards 11th house relationships. You may feel lonely or alone. Now, out of the Cancer dependency sphere, in Leo you should be strong enough to burn the bridges of the past, accept that which is over and move on with your life as an independent human being. This might also incorporate substance to fulfil the message within your 4th SN/10th house NN.
Whenever I read about little devils of thought/feelings creeping up, taking over and disturbing one's peace, I look towards the position of the natal and transiting positions of Black Moon Lilith in a chart. In a negative sense it often refers to that which never existed, never happened, was never meant to be in reality, yet lives as a deep feeling within that takes on a life of its own as if things really were and did happen. As such it can be a real little inner demon! Your natal Black Moon Lilith is on 17 Capricorn in your 5th house; it opposes your 11th house stellium. Simply said, it could mean that you make a reality (extra endorsed by it being in Capricorn) of 5th house affairs (which includes love affairs) that never actually existed and took place in real life. It's rather like fantasy playing with Cancer's rich imagination. Neptune in Libra, modern ruler your 7th house, squares your Venus-Moon. You make an image of your lovers that they don't meet with in real life, and you end up going through the real disillusions of love, presented by Moon-Venus-Neptune in your chart. Transiting Saturn may have brought home the results of such feelings during its transit of Cancer.
Yet, Black Moon Lilith in Capricorn in feminine charts has repeatedly shown itself to be those who wears the pants and are perfectly capable of taking care of, and responsibility for themselves, if only they would recognise it. BML at its best emphatically seems to refer to that which one doesn't need in order to survive, rather than what one does! Another link to the nodal axis, perhaps?
With transiting Black Moon Lilith approaching 14 degrees Virgo in your 1st house, you have allowed the little devil in yourself out recently. Transiting BML sextiled your natal Venus on 11 degr. Cancer and squared your natal Mars on 11 degr. Gemini at the beginning of this month and was within orb until quite recently. It has activated your loving feelings and mental thought patterns with images towards a man ( or maybe several with Gemini) to take some kind of action. Gemini penning a letter would fit the bill of such action. How the recipient received this action is another matter; Mars in Gemini can act angrily. I doubt his wife will sit back happily and accept it. Even if he tries to keep it a secret from her, she will probably suspect something if she knows him well, so it doesn't take much to guess what can happen when transiting Saturn reaches HIS Saturn-Pluto that opposes his natal Moon. Your little devil in you may have opened a can of worms. Yet that same BML in Virgo is also the inner strength within you to see things as and for what they REALLY are and not as you imagined them, or would long for them to be.
This is all taking place before the transit of Saturn to the Saturn-Pluto conjunction in the 12th house. The 12th house is similar to a lost and found dept. You can find whatever you've lost if you seek hard enough to find it.
If you are one who has always been governed (Leo) and controlled by others, or by a seemingly uncontrollable force stronger than yourself (Saturn-Pluto), time (Saturn) is approaching for you to take back SELF control of your life. Saturn rules your 5th house . Some part of you will demand that you let the controlling past 'die' (Pluto) and take responsibility for yourself and your actions (sextile Mars). This does appear to be very difficult for Sun-Moon stelliums in Cancer people, whose life revolves around emotional dependency and security of one kind or another. But, with Pluto, it also becomes a necessity in order to allow something totally new to begin.
F.