I just discovered that I'm aromantic, how do I tell my partner?

[lexthemouse]

I've been wondering if I was aromantic for a while but recently I've been questioning even more and after more research I've realized that I definitely am. I've always had a hard time telling the difference between platonic and romantic feelings, and in all my relationships after getting seriously romantic I get uncomfortable with affection and flirting. And I always wish we could just be friends.  I also  identify as asexual but I've known that for longer. I've been dating my partner for about 3, almost 4 months and we've been talking for about 6. We started as friends and eventually started going out on dates and then made it official. I've said I love them and all that other affectionate stuff but I'm realizing now I think I've always liked us better as friends because I don't like the idea of us romantically but I do like us platonically.  I feel horrible for only realizing this now and I feel as If I've been leading them on. I realize I said that  stuff because I thought that's what people  are supposed to say in a romantic/sexual relationship. The big problem I have is if I should keep this a secret or tell my partner. I don't want to hurt them and I know if I come out we'll definitely break up. But I also realize that keeping a secret like this won't help anything and our relationship will deteriorate on it's own. If anyone's gone through  a similar situation I'd be very glad for any advice at all.

TLDR: I'm asexual and don't know how to tell my partner

(PS: sorry for the rambling)

[lexthemouse]

I should also mention that I initiated the relationship (I asked them out to a date first) and they made it serious (asking me to be their partner)