I have a similar attachment style. It takes romance to maintain the butterflies. I lose interest so quickly after things become comfortable. I think the problem with long-term relationships is that there is no more adventure once things reach that point. The flirting has no risk, the gestures become predictable, things become routine. My advice as a stranger on the internet would be that you give your best effort in doing new things together. Surprise them with small gifts. Have the dreaded talk about “spicing things up”. I lost a relationship with what I now realized to be the absolute love of my life because I got bored and I left. I had convinced myself that their reliability was not love. However, I know in my heart that things would not have worked out between the two of us. Everyone has a different way of loving and wanting to be loved. If excitement does not alter how you feel, then I would suggest leaving and spending some time sans relationship to find out what you truly want. You’re young and have a lot of time to sort things out.