What should I use instead of "From my Knowledge"
Solution 1:
'Based on my personal experience' yields both an in-depth air while keeping a humble tone.
Solution 2:
A few suggestions I have are: "From my experience" or "In my experience..." If the summary is informal, you can say something along the lines of 'trust me, I'd know.' or 'from past experiences/events.' However, if this is a summary, I don't think you should be putting your opinions in at all. But I don't know what context you're writing in, so never mind.