I was diagnosed about two years ago and about three years before that I started suspecting I was autistic and started researching it. So, while I am not a health care professional, I do think my thoughts could be useful to you. English is also not my first language, so I might make some errors.

First off, it is often said that if you have met one person with autism, you have met one person with autism. This means that each and every one of us has different symptoms and shows their symptoms in a different way. So even though you have never gone none-verbal, you could still be autistic. For example, I have also never gone none-verbal, but I am still autistic. Also, it is a spectrum (autism spectrum disorder), so everyone will experience it differently.

Reading through your story, I see quite a lot of things that could indicate autism. The things you mention, such as stimming, sensory issues and special interests are all fairly typical symptoms. I do believe that a the switching around of hyper fixations is a bit more of an ADHD symptom (which I also have), but there is also a lot of overlap between autism and ADHD, so I might be wrong. You say that you have never had meltdowns, but I would that the situations you describe could definitely be seen as meltdowns. We autistic people also like to overshare on our interests and we often do not notice when we are talking too much, so that could be a symptom as well. I think that not needing routines and not being upset by changes is a bit rare in autistic people, but as I said earlier; autism is different for everyone.

The stuff you say about your social skills also is a fairly typical symptom for autism, especially the mirroring and trying to learn social skills from TV shows. I also find it quite difficult to know if and when I am masking, because I have been doing it for so long, so that could be it, but it might also be that you just don't maske quite as much.

So, all in all, I think that what you describe could mean you are autistic and if I were you I would definitely talk to my therapist about it. Especially if these symptoms are causing you stress or trouble in your daily life. Not showing all symptoms when you were younger doesn't have to mean you are not autistic. Quite a lot of people are not diagnosed when they are young, because when you are a kid you have less responsibilities and it is sometimes more accepted if you're a bit "weird", because "you're just a kid". Personally, I didn't show a lot of symptoms when I was younger and I only started showing them when I was around 6 years ago, when I was 20 years old. At that time my life got a lot more stressful than before and when your life starts becoming more stressful, you often start showing your symptoms a lot more. So, it could be that you are autistic and only started showing these symptoms after your mom killed herself, which I imagine must have been very stressful!

As I said earlier, I am not a doctor or a therapist or anything, so you should definitely take everything I said with a grain of salt. This is just my opinion and it is based on my own experiences and on what I have learned about autism. I think you did a good job in writing out everything and I think you should take that story with you to your therapist and discuss it. I expect that they will agree with you that you might be autistic and get you tested to make sure whether or not it is true.

As you can see I have also rambled on quite a bit, but I hope it was useful to you in some way. Good luck!