Victor you are right to be angry and it is a healthy sign that you are, with help you can channel that anger into determination which will begin your path to being a survivor.
You were sexually assaulted, do not doubt that, acknowledging what happened takes you further along the path to recovery.
As for being wrong about being sad that this is your first sexual experience? No it is not wrong, it is natural to feel that way. Maybe it would be helpful to try to look at it from a different angle, this was not a real sexual experience, it was assault and it is natural to feel sad about any assault. A real sexual experience should be a loving one and should be experienced with full consent, he did not have your consent and so he stole from you, if you can see it as the theft that that it was it may help.
Is it considered sex? No it most definitely is not, as @Valkyrie has said it is rape and assault, as such like I have already said it is also a type of theft. As also previously said it should be reported to the police.
It is natural to think about this or any form of assault, do not doubt that, with the right help you will think about it less, but it does need help and time.
By telling us about your feelings and what you been through you have already taken the first step to recovery and being a survivor. Seeing the Psychologist will be your next step, the help that you will receive there will help you find the strength to complete your journey.
If it helps then remember that you have our support and you are welcome to ask for and draw on that support any and every time that you need it.
I wish you well and wish that I could be of more help to you.