“The definition of a seudas mitzvah is one that is eaten in celebration of a mitzvah…”
Perhaps literally, but this definition implicitly devalues the whole concept of a siyum coupled with a seudas mitzvah. Most associate the concept with a significant degree of incremental effort in one’s limud torah, hashkafah, etc. Trivializing it with putting on teffilin, saying asher yatzar, toiveling in mikvah and other more routine mitzvos seems to be form over substance.
P.S. Try something innovative that you haven’t done before. Commit for shanayim mikra/echud targum for a least sefer Bereshis, try following R’ Eli’s nightly shiur in Hebrew (MDY home page link) for several weeks, volunteer to tutor a special needs bochur in a blat gemorah and celebrate a small accomplishment with him. All of these type events seem more in the spirit..