All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If the matter is just a feeling that you ejaculated while in reality this did not happen, then do not pay any attention to this and seek refuge in Allah from the accursed Satan.
Rinsing (the mouth) and inhalation (of water and blowing the nose) are among the Sunnan (plural of Sunnah; recommended acts) of Ghusl and are not obligations, according to the preponderant view of the scholars. Therefore, you do not have to redo your Ghusl (ritual bath) because you forgot Rinsing and inhalation.
Moreover, doubting about an act of worship after having finished it does not affect it because certainty is not overruled with doubt. This rule closes the doors of whispers to the Muslim.
We advise you work hard to get rid of this obsessive compulsive disorder by mentioning Allah as much as possible, especially by saying the morning and evening Athkaar (mention of Allah), as well as reciting the Quran, and performing Ruqyah. Earnestly supplicate Allah to cure you from this, as He is The Healer and there is no cure except His.
Allah knows best.