In the last 6 months he has become completely emotionally detached from me.
Whilst this is normal for PTSD, especially new and not knowing what is happening, there are methods around it. Early action is much better than after the fact, so well done.
His problems are his problems, have no doubt about that. There is nothing you can do to fix him, all you can do is adapt and make some changes to remove the present issues whilst he is going through treatment. Treatment alone will takes years, so you either adapt or separate.
You can't undo this, but you can implement strategies to change how he connects with you. What is he interested in? What does he like to do? Talk to him and ask him what things he would like to go and do together, and have a list ready if he has nothing on his mind. Start with things you know he likes, and you're willing to give a try and get involved.
Emotions come back in time and with hard self work, so until then, you're basically having to appeal to his fun and adventurous side that gives him please. This will likely also pertain to the bedroom... talk about role playing or whatever you feel comfortable with, in order to get connection from him again.
Connecting at these levels is probably the most he will be capable of until he works through his trauma, and even then, it takes time. Depending on the severity, think decade minimum.
There are some really good books available to help you, and help not just you, but also him... its a subtle form of acceptable manipulation basically, by you learning how to communicate better with him, based around what works and what doesn't work for you both, you can improve things immensely just from your interaction with him, and as a consequence, he will actually also improve when methods are done right.
Based on your specifics... I would recommend you read first:
Dead Link Removed which is like a supporter workbook. It contains the important info, but is focused on extracting the specific issues from you and you writing them down. You work through the book doing this, building your list and involving your partner at opportune times, progressively enhancing your communication process and fixing some of the basic problems and barriers you need to get through to repair your relationship.
Once you get through that, a good book that both of you can use is:
Dead Link Removed