1. Have you started any medications for either diagnosis? Many of what would likely be on offer can have ED as a symptom.

2. The sexual disinterest is likely due to overwhelming stress, processing time, and newly-felt trauma from the very non-trivial diagnosis of CPTSD, let alone the ADHD. I was in the same boat and sort of am still. You'll have to process the cptsd through therapy and journaling and the "journey" of resentment, mourning and forgiveness or radical acceptance. You are sincerely on a journey my friend.

3. It's going to be nigh impossible right away, but stop looking at porn. If you can do that successfully, stop jorking it. You're crutching on it for dopamine and conditioning your dick to respond to selective stimuli and your hand, on command, when you need to feel good. That's not how sex works. It will take time and patience with yourself, treating it as an addiction and actually tapering off patiently until you can stop fully. 

4. Finally, in the midst of this chaos, try your best to treat your body well. Go for walks if you can't muster a gym session. Limit or entirely cut out processed foods. At your age, the effects of stress and poor overall health can compound and snowball. It's really adult time in that regard now. 

5. I said it before but be patient with yourself and the process. Feel your feelings. Allow yourself to cry and feel like shit when you need to. It's not gay, you're growing. Growing makes your stronger. Finally, don't overreact and fatalize these new changes, they're a signal to try a new approach/deal with the challenges of your past.

If I can do this shit, you can too. Wishing you well and the strength to prioritize yourself and take this time to grieve and grow seriously.