I don't know why but naturally I got a strong feeling before discharge of semen but at end I could control it.
Now I can say that I didn't discharge semen and due to pressure I couldn't control urine from being discharged so,
should I perform Ghusal?
To be honest, i assume that your question is complex (somewhat), actually I didn't figure it out completely. anyhow, I hope my response be related to your question and can help you (God willing)
In accordance with the ruling(Fatwa) of Imam Khomeini:
The Ghusl is not wajib(mandatory) in case the semen moves from its place and doesn't get out, or you doubt that the semen has gone out or not. But if some water( after a while) gets out from the body and you are sure that is semen (that had moved but didn't get out), leads to the Wajib Ghusl(Jenabah).
(Tozihul-Masaael, Al-Mhshi lel-Imam-Khomeini, Vol.1, Pages 208 & 211)
Of course you can see the link below which consists of another similar issue and it could help you as well.
www.islamquest.net (in Arabic and Farsi)
www.islamquest.net (in Farsi)