how to break the news about crossdressing to my girlfriend?

Hi everyone. To give you some background: my girlfriend and I have a solid relationship with plenty of love between us. For years now, I’ve enjoyed wearing women’s clothes because they make me feel naturally right, not just kinky or doing it for fun. It’s been tough keeping this part of myself hidden from her after nearly two years together; she deserves to know. My main worry is how she’ll react when I bring up my ‘fetish’. I don’t think she’ll be mad since she enjoys helping me explore my fantasies, but I’m caught between the fear of embarrassment if I tell her and a worse kind if she finds out later on.

That’s why I’ve come to this excellent online community for advice.

Thanks in advance!