Regarding negative feelings after meditation, I am grateful that you mentioned it because I had these too and this is the first time I've heard from anyone with a similar experience.
I took up regular meditation last Spring, sitting 30-40 minutes daily in my best approximation of zazen. I found the meditation quite relaxing and on some days I felt much better afterwards or had small insights about my life. Other days were not so pleasant. I believe I experienced a sharper awareness of the stress I felt at work (which in the past I would have denied feeling at all) and I was much more likely to notice when I became distracted at work, resulting in growing frustration and anxiety. I think it also made me more aware of the shallowness of my relationships with my coworkers and my own reluctance to engage with them.
Overall I suppose it's been a positive and educational experience.
I took up regular meditation last Spring, sitting 30-40 minutes daily in my best approximation of zazen. I found the meditation quite relaxing and on some days I felt much better afterwards or had small insights about my life. Other days were not so pleasant. I believe I experienced a sharper awareness of the stress I felt at work (which in the past I would have denied feeling at all) and I was much more likely to notice when I became distracted at work, resulting in growing frustration and anxiety. I think it also made me more aware of the shallowness of my relationships with my coworkers and my own reluctance to engage with them.
Overall I suppose it's been a positive and educational experience.