No one's trying to put you down or make you feel unwelcome. I think the point that they were trying to make is that we can't give you the answers you're looking for.
Being trans is for the most part a self diagnosed issue. There are gender therapists who can help you determine if you are trans, but only you can really say "yes I am trans." I know how difficult this is for you, it's difficult for all of us. There are many would like someone to be able to do an exam take our pulse, check our reflexes and be able to say "Ok well I think it's safe to say that you are Transgender, here's a referral." But this just can't happen.
Remember, only you can really know who you are. We're here to help you in any way we can but we can't diagnose you or tell you who you are.
As said above, I hope you stick around. I remember being confused when I first got here and having trouble figuring myself out. But being here has helped me a lot. I hope we can help you too.