I've created two conditions for my Omegaverse: Rejection Syndrome and Pseudo-Mate Syndrome.
Rejection Syndrome is technically a variety of Depression that is triggered by being rejected by your Mate. It ranges from just feeling sad and thinking about what they got rejected for for a few hours, to spending years obsessed with the rejection unable to focus and even in physical pain from how strong the emotional pain was. The easiest cure is for your Mate to comfort you, because they aren't rejecting you entirely, but sometimes it becomes prolonged and they require medication to assist (think anti-depressants). It is possible to cure by taking their mind off of it, but due to the fixation element it's very difficult to do. Sometimes Rejection Syndrome kicks in alongside grief (like, your Mate died) and those situations are always very complex... The in-universe explanation is that it developed as a way to ensure the harmony of the relationship. You have to think about how your actions could affect your Mate. Because there can be consequences if the relationship becomes difficult
Pseudo-Mate Syndrome is basically what happens when you are so in love with someone that your body is convinced you are already mates with that person. This typically can only occur after YEARS of wanting to mate with someone. All the normal Mate stuff applies: heats/ruts sync up, you become way more intuitive to their moods (actually mating causes an empathic bond), other people's scents (especially aroused) become repulsive, etc. of course since by definition you are not in a relationship with this condition your "Mate" may reject you, causing the aforementioned Rejection Syndrome. The cures are: Become Mates, or fall out of love.
I have three people with Pseudo-Mate and all three experience Rejection Syndrome.
All three are Alphas coincidentally, but all dynamics are able to develop these conditions.
(one has RSD and low self esteem and so experiences Rejection Syndrome very easily. One loses his intended Mate to, what he thinks is Death, but she turns out to be alive and experiences the Grief variant of Rejection Syndrome. And the last has a very volatile relationship with his beloved and they fight often.)
One of these (the Last one) actually has a different Omega whom he is very close to, and regularly spends Heats with in a non sexual manner and oh boy isn't it going to be interesting when he can't comfort his friend because suddenly he stinks
THIS IS WHAT THE FUCK I’M TALKING ABOUT!!!!!!!!
As a hurt/comfort bitch, this is just great. I wish I could give you a prize. Literally 10/10.
I will be applying this to any future fics.