Concerned that this might be a loveless relationship?

We've been together for three years nearly, but sometimes I wonder if we're only together simply because we've learnt to depend on each other. We make each other feel secure. We share business goals and stuff and I'm sure that if I wanted it to we could last for a while.. that's just how stable we are. But I feel like the relationship lacks emotions We had a really negative start to the relationship so since then we kind of skipped that sweet beginning phase and it seriously feels like we've been husband and wife for years and we've lost that love for each other. We won't split up, though.
I'm just wondering what you think. In our composite, we have a strong 7th house but Saturn is really strong so I don't know if that's a burden on our relationship.
In our synastry, his Venus is practically unaspected. It has no major aspect within 8 degrees (neither does out composite Venus).
I'll post both our synastry and composite charts and hopefully somebody here will be able to give me some advice.

Also attached synastry aspects. In the synastry chart, I'm the outer chart.

I haven't seen a composite quite like that. All the important elements for a love relationship really aren't there - no Sun-Venus, Venus-Mars, and all the other important Moon and Venus stuff is so wide in the orbs as to be non-existent. There is a strong past life component and you have been associated before, but it appears mostly to be in the realm of friendship. I've never seen a composite with NO NODE aspects. There really is no karmic goal here other than extended friendship. It is easy to be in this relationship because you were before. The Sun makes a conjunction with Uranus which can make it exciting, but typically such an aspect burns hot and bright and then fades out quickly. The only thing that saves it is the Sun in Saturn's sign of Capricorn, and Saturn in a loose trine with Venus to provide stability. Venus being in Cancer and having this trine gives a very close sense of comfort and security which can make up for the lack of other real personal aspects. The Sun in 7th also gives assistance here. How does the Venus in 12th house feel for you? Do you provide comfort and security for one another effortlessly, always knowing what the other needs without verbal announcement? Or is it something that is hidden from others - people who don't know you don't suspect you are together, along with the loose square of Venus to Moon? Just wondering how that works out in your relationship. Moon is also in Virgo, not a very expressive sign for emotions, although at least an adaptable and female sign, not rigid like perhaps Aquarius would be. The other saving grace is Venus in close quintile to Mars - not an optimal Venus-Mars aspect but better than nothing, giving some ability to provide comfort and closeness, providing for your partner even though you may not be up to it - just easy going without effort, also fulfilling the Venus Cancerian needs.
In short, you are right, it is what it is, and likely will not be much different. Safe, predictable, sometimes a little bit of edge but everything still fits well even if a tad loose here and there. It is a car that won't win any races or awards but gets you from A to B without fuss.
You must have been feeling some tension lately with transiting Uranus right on the MC and square and semisquare many planets - something that has been going on for a while and will continue to do so for a few more months. More concerning is transiting Pluto right on the DSC, soon to hit your Merc and Sun. Decisions will have to made - are you satisfied with the status quo? Transiting Neptune will be square the Node soon too - you will soon be questioning everything about the relationship, its goals, its purposes, what you get out of it and whether it is providing for your spiritual growth or is just stagnating it. Transiting Jupiter is on the ASC, so a new dawn is approaching in this soul-coupling of yours that has likely gone on for several lifetimes. I'm suspecting this is why you posted to the forum and you may have already been asking these questions. Transiting Vesta will be squaring your Vertex soon also, so situations and events will begin to manifest, reflecting your fears and sub-conscious desires. Don't attack the events when they occur, they are part of this process and the questioning that is occurring now.

I don't think we'd be friends if we ended. If we weren't instantly pulled together as a couple, I don't think we would've got along as just friends. His Mars square my Sun makes things too complicated at times. It seems like he literally needs me to argue with him.
No, that's not always the case. We understand each others emotional needs, but there's a mystery there, too. When we're together, I seem to understand his moods better than he understands mine. I just know when I should and shouldn't do certain things. When we're together, people don't see us as a couple. We don't hold hands or anything like that, we never have (he doesn't like it). Very early on I noticed how far we'd stand apart from each other when we're together in person. That was strange for me, perhaps not for him, he can be quite a distant character. I think people find our relationship odd, and see something is a bit off with us. I remember bringing him to meet my family and they were looking from me to him with puzzled expressions, as though the emotional distance between us was tangible. I don't understand our connection and I don't know how to describe it, either, but I know it's unbreakable. There's a really unconscious pull to each other, I think. My Venus and Moon are in his 4th house- perhaps this is the pull I'm referring to.

Turns out I may have gotten his birth time wrong. His hospital documents say a time, but do not specify a.m or p.m, though his Mum has told him he was "born after 10pm." I had him down as born in the morning. the good thing is that our composite Moon is not conjunct Mars, and has a few harmonious aspects. Venus would still be poorly aspected (with a closer square to Moon, and the trine with Saturn). The Capricorn stellium is shifted into the 4th house. NN is still unaspected... and then there's Saturn in the 5th