Shalom, Don't worry, as long as the candle is lit you can correct anything. First you should learn from that never to push a Mitzvah off. When you have the opportunity to perform a Mitzvah, especially when it's time bound like Teffilin, you must jump on the opportunity and do the Mitzvah right away. The Mitzvot have to be the highest priority. The way to fix a day of putting Teffilin, is to make now other Jews put Teffilin on. When I became religious I was 27 years old and I calculated how many times I did not put Teffilin on from 13 till that day. It was almost 4000 times that I missed the great Mitzvah of Teffilin. Since one can not really correct a positive Mitzvah he/she missed, the way I found to correct almost 4000 times of missing Teffilin was to make as many as men possible put Teffilin on, and I went in the streets looking for Jews and asking them to put Teffilin on. And Thank G-d I was successful to make thousands of Jewish men put Teffilin on and hundreds of them purchased their own pair and put Teffilin on everyday. So that should be your goal right now, to make as many Jewish men put Teffilin on! Good luck and don't let this put you down! rise up and keep moving!! All the best, R. Alon Anava