Do I really love them? The question relationship OCD asks
The relationship might be good. The doubting is destroying your enjoyment of it. Relationship OCD turns the ordinary ambiguity of love into a threat that must be resolved.

Do I really love them? Are they the one? Why did I notice that other person, and does it mean something? You monitor your feelings during every hug, checking for the right amount of warmth. You compare your relationship with everyone else's. You confess your doubts, and feel better for an hour, and then the doubt is back in a slightly different form.
The relationship might be good. It might be the best thing in your life. And the doubting is destroying your ability to enjoy it.
What ROCD is
Relationship OCD turns the normal ambiguity of love into a threat that must be resolved. Everyone who has ever been in a relationship has had moments of doubt, of noticing someone else, of wondering whether the feeling is what it should be. In most people those moments pass, unexamined, because nobody demanded an answer. In ROCD, the moment becomes a question, the question becomes urgent, and the search for certainty begins.
The problem is the demand for certainty about the relationship.
How it works
The engine is the same one that runs every form of OCD. An intrusive doubt arrives: do I love them enough? The doubt is unbearable. Something is done to resolve it. In ROCD the compulsions are mostly mental and relational: checking your feelings, testing them against an imagined standard, comparing, replaying moments, seeking reassurance, confessing.
Each compulsion brings a moment of relief. And each teaches the brain that the question was important enough to need answering, so it comes back louder. Checking whether you feel enough during a hug guarantees that you will feel less, because attention turned on a feeling always dampens it. Comparing your relationship with others guarantees you will find one that looks better. The search manufactures the doubt.
Why ROCD doubts are different from real doubts
Every relationship involves real doubts sometimes, and I am not going to tell you that yours are all OCD. What I can tell you is that ROCD doubts behave differently, and the difference is the tell.
They demand certainty, when ordinary relationship doubts are content to sit alongside commitment. They return immediately after reassurance, when a real doubt, once addressed, tends to stay addressed. And they contradict your own experience of the relationship: you can be happy, feel loved, enjoy the person, and still be tormented by the question of whether it is real. A doubt that keeps returning in the face of the evidence is the machinery, not information about the relationship.
What treatment does not do
Therapy does not tell you whether to stay. I am not going to assess your relationship and give a verdict, and I would be wary of anyone who offered to. The goal is to quiet the obsessional doubting so that whatever you decide is genuinely your decision, made from a settled place rather than from the middle of a spiral.
I will also not reassure you that you love them. That would be one more compulsion, one that happens to involve me, and the relief would last exactly as long as it always does.
What treatment does
Using CBT with exposure and response prevention, we identify the checking, comparing, confessing and reassurance-seeking that keep the doubt alive. Then we practise letting the questions stand unanswered while you get on with loving imperfectly, like everyone else. That means noticing the urge to check how you feel and declining. Letting the comparison arrive and not following it. Having the doubt and not confessing it. The anxiety rises, and then, given nothing to feed on, it falls, and the question loses its grip.
Partners are sometimes invited in for a session, only with your agreement. Reassurance-seeking usually involves them, and a little shared understanding of what is happening goes a long way towards withdrawing the reassurance kindly rather than abruptly. Whether your partner knows you are having therapy is entirely your choice.
A typical course runs 12 to 16 weekly sessions. Many people find that once the checking stops, the question of the relationship becomes much clearer, sometimes because the doubt fades and sometimes because they can finally see the relationship as it is rather than through the interrogation.
If the question will not leave you alone, there is more on how I treat relationship OCD.