Any experience or advice on medication for negative rumination?

I tried an anti-depressant once and it was an incredibly scary experience. The only description I have is that they seemed to lock me out of most of the brain I use. I wonder if this is not a problem for non-autistic individuals as their brains are wired different. Perhaps this is the part of the brain which is used for problem-solving. 

There were a LOT of things in my life at one time I didn't consider fixable. Most of them were either caused from financial hardship or the wrong perspective. I changed so many perspectives and that actually helped with finances. We all need relationships, but not the wrong ones. And while I do work hard to maintain a better life and am nearing 50 still saving to buy a house, my life is incredibly different than 30 years ago. 

Now anti-anxiety medication, when taken with a bit of discipline and in very small doses as a way to take off some of the pressure so I can actually make sound changes to my life, though slow, has been really helpful.

All this to say, if there's more to the story and specifics perhaps there's some group wisdom here and ideas to try and troubleshoot problems with.

I tried an anti-depressant once and it was an incredibly scary experience. The only description I have is that they seemed to lock me out of most of the brain I use. I wonder if this is not a problem for non-autistic individuals as their brains are wired different. Perhaps this is the part of the brain which is used for problem-solving. 

There were a LOT of things in my life at one time I didn't consider fixable. Most of them were either caused from financial hardship or the wrong perspective. I changed so many perspectives and that actually helped with finances. We all need relationships, but not the wrong ones. And while I do work hard to maintain a better life and am nearing 50 still saving to buy a house, my life is incredibly different than 30 years ago. 

Now anti-anxiety medication, when taken with a bit of discipline and in very small doses as a way to take off some of the pressure so I can actually make sound changes to my life, though slow, has been really helpful.

All this to say, if there's more to the story and specifics perhaps there's some group wisdom here and ideas to try and troubleshoot problems with.

Yes - I’d say my experience of taking anti-depressants was the second most distressing and scary experience of my life (and I’ve had a lot of scary and distressing experiences!). 
live been reading recently about hypersensitive interoception and I think this has a role to play in why I find side effects so hard to cope with. 
I also think that autistic people can have very complex psychological histories - plus the complexity of what we all experience as human beings anyway - and because of that there is rarely any ONE answer to our problems. Certainly no one medication that will solve our complex issues. But I know it can have a role and can help some - and harm others. 
I feel strongly that what autistic people need is an autism centred mental health services  - but that’s not available to most of us sadly. So we end up going on our on journeys - trying to work these things out for ourselves through various routes. That’s why this community is so helpful - because so many of us are trying to help ourselves and so so hopefully provide support to others who are on similar journeys. 
Trying meditation, CBT etc though is a lot less risky than medication. Medication can be a bit of a shock to the system (it certainly was to mine) - and if you’re already feeling fragile it can be hard to cope with a shock to the system. So take care when trying a new medication, and make sure you have support in case it does not suit you. 
The doctors prescribing these medications don’t even know how they work - there are still many unknowns in medicine. There are gentler ways to find peace - but they take effort and time. Personally I realise now that I needed to work out why I felt so bad - and make changes. No tablet could ever have addressed the underlying causes for my distress.  Medication doesn’t solve the unhelpful thinking patterns we have, it doesn’t remove past trauma, it doesn’t make the society kinder or more easy to live in. It doesn’t provide profound and lasting answers to anything. However I have heard people say it gives them ‘breathing space’ to allow them to deal with those things - and I have to respect and trust that that is the experience some people have - and I’m happy for them. 
None of these decisions are easy. I also had the prescription for a long time before actually working up the courage to take them. All I can say is that in my experience they made me feel much much worse - which bearing in mind that I was already in a very bad way was the very last thing I needed. 

Thanks for replying to this - it's appreciated.

I was concerned about becoming some chemically-numbed zombie or losing my 'spark' and thankfully I have a couple of people close to me with relevant experience on the medical side and the consensus seems to be that while that was definitely a problem in the 80s/90s it's much less of an issue now where SSRIs/SNRIs have improved so much, doses are much more carefully controlled and GPs and patients are much better educated about the risk/reward balance. 

Having said that there does still seem to be risks and potentially major side effects and an element of hit/miss uncertainty.

Thanks.