You won't be able to have a simple trigger based on if a flow making the changes vs a person.
(There is a way which is not good, not recommended, but works in very specific situations. It would be based on Modified By, so like if your flow is making the changes, your name goes into the Modified By. So then if someone else manually makes a change, the flow is triggered and checks the Modified By column to see if it was your name or different. Of course this doesn't work if flows are shared or you are the one manually changing items.)
You will have to set up your list and your flow logic to do what you want. That may include putting some kind of signal/status column(s) that you can use to check. Like the other flow makes a change in that status column and then when the new flow is triggered it checks the column. (Of course now you have to manage the new status column and when it is changed.)
Or you could see if there is a way to combine your other flow and the new flow to work together within the same flow. So you could delete the separate flows and just have a single larger flow.
That is the hard part and creative part of designing flow processes.
