As the others wrote, Neptune sitting on descendent is a big warning sign, and it is square Venus of love. He's a big mystery, hard to decipher through the fog and vapours that surround him.
Venus rules your 2nd of self esteem, which is being diluted by the contact. Venus also rules your midheaven of reputation.
Moon, which is the question, is in ascendent, asking about yourself, and in the sign of libra. Libra wants a needs a partner. And it is ruled by Venus, bringing us back to the conflict he is creating that effects your self esteem.
You are mercury, last passed over Uranus of separations.
Mercury in taurus is ruled by Venus, again, back to the same conflict here.
Mercury is almost exactly conjunct sun, ruler of the 12th house of restrictions and also the subconscious. This contact is stirring up a lot of inner turmoil in you. The conjunction also occurs on the cusp of the 9th house of inner wisdom, so this is an important situation for you, you stand to resolve a lot of inner problems that have been holding you back, above all in relationships.
Mercury is 22 minutes from conjunction with sun. At 17 minutes it will be cazimi, and this is so close that we could almost concede it is cazimi.
A planet close to the sun loses its power and gets "burned up" by the heat of the sun.
However, in cazimi, it becomes strengthened.
It's comparable to the difference between being half a mile from the eye of a hurricane with all the terrible turmoil tossing you around, and then being precisely in the eye. You arrive at a point of calm and stillness that allows you to look around and catch your breath. You regain your strength.
This is where you are now.
So, were in a relationship with him, you separated from, he returned and is not being civil.
From the surface, the solution looks simple enough, just send him away again.
So why haven't you? Deep down you would like it to work out.
You apparently have to come to grips with something personal here that you haven't resolved yet, and it has to do with your approach to relationships.
Mercury coming together with sun is you bonding with your subconscious.
Sun is the ego, in the house of your inner knowledge, your higher thoughts. This is an opportunity for you to dig deeper and come face to face with this underlying conflict.
The importance of Venus in this chart, elevated on your midheaven of reputation, representing your self esteem, and in open conflict with the relationship, is a key.
He is being illusive, but in his fall he is in reality feeling weak.
In your 5th of love, it is his 11th of friendship, so his intentions, muddied as they might seem through Neptune, aren't really negative.
He is separating from Pluto, bullying, inner turmoil and transformation.
Pluto rules his 9th of higher knowledge.
Jupiter will soon go retrograde, giving him a chance to rethink things.
You mercury will trine him before he goes retrograde, but first mercury will square mars.
Mars rules your 8th house, and the 3rd, so you will have a lot to discuss (3rd) with him about sexual matters (8th), and it won't be easy, before you match up with him.
If you can identify and resolve your 12th house and Venus conflicts, you will be stronger and will have rebuilt your self esteem. And then you can tackle this relationship, and eventually others in the future.