Judging from what you've said about the situation, consider the possibility that you are not a good fit with your child. This might not be related to his autism; plenty of NT families go through this too, and there's no blame on you or the kid. In short, some parents and child can easily relate to each other while some can't. In the case that they can't, there might be too big of a difference of temperament and personality for both parties to operate on intuition. I don't have good advice for this, but try to understand his reasoning for doing things, and avoid jumping to conclusions that he's doing things that are bad for him just because you don't see the reasoning.
Not that I dismiss them and never have. But saying "don't worry this is a minor situation and it will get better" with all good intentions isn't the right thing to say because he takes it completely differently.
Sounds like depression & anxiety working its way. When I was depressed I often interpreted things in a helpless way. So "don't worry this is a minor situation" became interpreted as "I can't even work through a minor situation," which added on to my helplessness. This is pretty relatable. I'm not sure if your son understood that you were trying to help but just not succeeding. I always knew when others were trying to help but failing miserably, so it didn't bother me as much, but some people with depression can't tell. It might be worthwhile to tell him that you didn't realize he was interpreting it differently. For the support talk, I would suggest not saying things like "
it's small and you can get over it." Often in my head, I was thinking, it's
not small and I
can't get over it, I'm a failure for not being able to get over something so small, etc. Instead, suggest that you'll always be there to help if he needs help with something.
we are down to "it must be the meds aren't working we need help."
I'm by no means a professional or even close to one, but here are my two-cents. Keep pumping someone with meds isn't the most helpful for them to figure out things. Meds are only helpful when the condition legitimately has mostly biological causes, like postpartum depression and menopause. Teenagers are more likely to get depressed because of hormones, but that's far from the only cause. Most of the time it's because of rapid changes in situations, and that kids are growing, trying to make sense of a lot of things. Since you mentioned this probably started in January, it's probably more than just teenage hormones. You child needs to learn what is causing him anxiety and go from there. If he has difficulties identifying his mental state, this will be hard. I agree with how someone else said that saying "I don't know" means that the situation is too much for him to comprehend. I don't have good suggestions. Maybe finding a therapist in CBT? The focus should be someone who could work with thought patterns.
How do I get him out of the house to do social things when he doesn't want to? The only way I know how is to say "ok you don't have to go but I also don't have to provide power to your room" so he can't be on the computer.
Why is it so important for him to get out of the house? If he's depressed, that'll only make his life harder, a lot harder. If he's into computer games, there is a good possibility that he's making real friendships online. My teenage years weren't that long ago, and I grew up with the Internet. My observation is that older adults often have a cynical view of online friends, but I've developed deep connections with people I met online (one of which I met in middle school and stayed friends). Personally I never felt the urge to head out as a teenager, except for fulfilling expectations, like school or buying necessities. This goes back to the "good fit" thing I mentioned at the top. Social things that work for you might not work for him.
Also I think there is a visual stim element of computer games. Look into whether he's seeking visual stimulation with the games, although it might be hard for him to answer the question.
Personally I don't agree with the approach of taking away his privileges many people have mentioned here. That will turn into a power struggle between you and your child fast, especially when he's a teenager. Coupled with depression, he's likely going to think you can basically control whatever he has, and he has no power over what he wants. Granted, it makes sense to take things away when he misbehaves, but for a child that often feels like "I have to obey my parents or they'll do things." The "because I said so" approach never worked for me.
Also, I grew up in a culture where the idea of "privilege" specifically as the entertainment for children is often not noted. Never quite understood why some things (i.e. TV or games) are considered privileges in the west, per se. I understand taking them away as a punishment, but not the idea that they are some sort of "add-ons." Adults watch TV too, but do they stop themselves from watching TV when they do something wrong? No. A power imbalance right here. And if anything above basic survival needs are privileges, then almost everything is a privilege. Reading the newspaper, going to workout, drawing, any hobbies, etc. When was the last time you heard someone lose that kind of privilege? Listening to music on your phone is a privilege, but practicing an instrument is not? I personally love reading, and never had that "privilege" taken away as a punishment. Anyways, going off-topic here...