Welcome to the site. As many have said before, glad you are here, but sorry that you needed to find us. Know that we, like you, have many quesitons and experiences. No question is stupid. We understand.
A couple of things from your post. Without your consent, either the first time, or the second time, or whatever time, its sexual assault. No question about that. You were sexually assaulted. In this you are by no means alone. I was too. Practically all of us here were assulted/abused.
The second thing from your post is the aftermath of the assault. My first sexual experience was also with a man, but at an age when I could not have offered a consent even if I wanted to. The feelings that this left me were terrible, gut wrenching confusion that can take a long time to sort out. My subsequent sexual relations with girlfriends, and then my wife were all affected, tainted by the experience. If you can, look for a good therapist to help you sort out the feelings. Read the posts here. Take your time, don't rush, take it easy on yourself. We are all here to help you get through this. This was not your fault.
Feel free to send me a PM, or to post here, or anywhere else on here for that matter. Here you are believed. You are valued. And know that recovery is possible.
Hang in there!
My name is Jim
WoR Mysthaven 2008, Level 2 WoR Alta 2009, Kirkridge 2010, 2011, Oprah 200 men