Can be internalized homophobia the cause of anxiety ?

Yes, definitely. If you are uncomfortable with who you are because of what you've been taught to believe about LGBTQIA people, it's natural that you would feel anxiety about your sexuality falling somewhere on that spectrum.

It definitely can be! Internalized homophobia can be so damaging for lgbt kids and even adults. It's hard to work through. There's so many of us who have cried over our love and our lives because of homophobia from the world and that which we internalize.

It surely can. If you live or have lived in an homophic environment, it is possible that you have internalized homophobia. It's not your fault, the internalization of ideas can happen, but you can fight it and set mind your mind free from prejudices. Day by day start analyzing your thoughts to realize if what you think is really what your believe or what you've been told. Analyzing your thoughts and reality critically can help. Open-mindedness is something you can work on, and acquiring it can really make your life better.