Hi Tammy you sound like a pretty understanding person and he is lucky in a way.
The dating site thing like others have said is more of an outlet IMO.I have done that myself but I was not in a relationship.
I do have an issue with you "finding" his clothes stash and going thru his phone "finding pics" Honey that is called snooping and not a very nice thing to do.How would you like him snooping in your stuff trying to find "dirty" little secrets? Shame on you.
He is scared and at 24 being "outed" is by far the worst thing that can happen. He will lose friends and possibly family if they found out he likes to CD.
He is in denial and will do anything not to be discovered.
I have had partners snoop in my stuff and it has caused me to walk out on what could have been a great relationship.
Good luck breaking the ice because it looks like he doesn't trust you either and can you blame him?
I hope you two can work things out I really do.



crossdressing...theirs an app for that 


, It sounds like shame and embarrassment on his part.
A closeted crossdresser has years of conditioning to hide his behavior and it's probably backed up by as many years of self-loathing. He's probably afraid to come clean about it both because he doesn't understand it himself and because he can't imagine how anyone could love him if they find out about this awful vice (in his mind.) You're a total hero if you ride this out. It seems like you're saying the right things, you just need to crack through the shell. Maybe you should encourage him to come here and read a bit -- find out he's not alone; he's not broken and he can be as loved as anyone else.