So, from where I see at the moment, thoughts are a sensation that arise and pass away just like all other sensations, hear, touch etc.
Great! Yes, thoughts are somewhat equal to sensations in the way that they are experienced directly, now. Thoughts appear as a) mental words or b) mental images
The contents of the thoughts are not in reality, but can trigger physical reactions of the body, which also includes emotional reactions.
What you refer to as "content of thought" I would call the thought itself. A thought can indeed trigger physical reactions or emotions. But the content of the thought - that which the thought is about
as if it existed in reality - is just not there in reality.
Can you see this?
I invite you to do
another exercise for further clarification:
Think of a cup. Get a very clear picture in your mind. See clearly the size, shape, colour and volume of the cup. Notice whether it is decorated or plain. Notice whether it has a handle. Notice whether it is heavy or fragile. Do you have a clear picture in mind?
Now, can you physically grasp that image of a cup? Can you pour tea into it?
Can you drink from it?
Is there a ‘real’ cup or just a mental image (a thought) of a cup?
Is the content of the mental image (the cup) ‘real’?
If so, you should be able to pour tea in into it.
Thoughts are real only as arising mental images or words, their ‘presence’ cannot be denied.
However their contents - what they are about - are not ‘real’, they are just fantasies.
Further exercise:
Throughout a day investigate the content of thoughts.
When there is a thought (mental image/words) check whether its content (what it’s about) is also
here, in reality - or whether the content is just imagination.
Let me know how it goes :-)