Why do I feel so alone in my relationship?

Because you are giving more than taking and the other person is not trying hard as you in the realtionship. You might be distant from each other as well and don't know how to communicate like you used to

Maybe you haven't gotten the deserved affection, or maybe you aren't feeling the right things in the relationship. Talk to your partner about it.

Maybe he/she does give enough attention in the relationship, or you see each other not that much....

It is common to feel alone in a relationship when you feel the other person does not understand you fully. Be open about the way you feel and see if this helps form a stronger bond between you.

Maybe, you both don't spend much time together or you're not connected closely. Try to get to know each other more.

This could be due to a lot of reasons. Maybe your partner doesn't really talk to you, maybe the conversations feel empty and thoughtless, maybe it's just in your head. Try thinking if the issue is really there, if you are 100% sure there is an issue, try talking to your partner. I'm sure he/she will understand and be happy to talk about it.

Feeling alone can be heavily related to lack of communication in a relationship. It is difficult to feel loved or wanted in a relationship when you don't feel like they want to be around you which can also be caused by anxiety making you overthink and effect the trust of a relationship.

Do you have the same goal for the relationship in mind? Have you talked about your feelings? Have you tried Expressing what you feel?

In my personal experience, feeling alone in a relationship was the result of not having the intimate connection to the other person. The interesting thing was that working on myself first, getting to know myself was the most important part in uncovering ways to recognize what was missing.

Living in a relationship, especially for a longer period of time, sometimes makes us think that its granted, therefore we do not focus on our partner that much anymore, many things come and distract us one from an other. At some point we are to realise, that the only thing left in common with our partner is a label "relationship", and that in fact we have nothing in common nor really know each other anymore. From my experience, it is important to include you partner in your life actively - everyone changes, and being with someone is also keeping up with them, but if we already are at the point of loneliness and pointlessness of a relationship, why not to get to know one an other again?