If you do what I suggested it will solve all of your problems...
Searching in this way shows only the threads that you have posted in, not each and every post you made. It also shows which ones have new responses because they will be highlighted. That way you know which ones you might want to look at again.
And if you make just one post in a thread you want to follow, then that solves your second issue, because then those threads will also show up when you search for your posts, and they will be highlighted if they have new responses in them that you have not yet read.
I use the Search feature, click on Advanced Search, and then search for my own posts.
Searching in this way shows only the threads that you have posted in, not each and every post you made. It also shows which ones have new responses because they will be highlighted. That way you know which ones you might want to look at again.
And if you make just one post in a thread you want to follow, then that solves your second issue, because then those threads will also show up when you search for your posts, and they will be highlighted if they have new responses in them that you have not yet read.