Sack your astrologer.... Scorpio and Aquarius relationships are challenging because they are both fixed and square to one another, some people need a challenging relationship or they get too much of their own way. ANY astrological combination can be made good with patience and love. If your chart is strong you will want a relationship that challenges you, and vice versa, then it may be a perfect relationship. Bottom line it all depends on the natal chart of the individuals involved.
Bottom line is how after a year do you feel about him? If you like him sit him down, give him boundaries and reassure him. If he is a strong scorpio type simply give him a lot of reassurance that you are loyal to him. You'd be suprised how far simply understanding his insecurity and being supportive of him will go.
If you are either unsure or want to break it off, you will need to be really firm with him, explain you are finding him suffocating because you need more freedom etc... and that there is not someone else on the scene.
Scorpios can take infidelity really badly
Good luck but to be honest you don't sound too certain of this guy after a year, put the poor sod out his missery.
As for astorlogy, Synistry is the reason scorps andaquas are at odds, sometimes in a good way, but you might want to try composite, which is of the relationship itself.