It seems a little pointless to use "too" at all. The fact that you are saying "feel the same" means that you must be stating that you are feeling an emotion which is also being felt by someone else.
I feel the same.
You might be able to use it if you were the third person to state their feelings. In the following dialogue, you are person C.
A: I feel really sad about his death.
B: I feel the same.
C: I, too, feel the same.
C: I feel the same too.
You are saying "too" to indicate that you are speaking in addition to person B.