This subject has been discussed before in this Club. Please use the search for the word "tie" and you will find all the messages in this subject.
Anyway, let us analyse your argument:
1. You won 3 matches, and your rating went up because of that, right?
2. You did not win the tourney; it was a tie, right? If you played a tiebreaker there is a 50/50 chance that you will lose. This is why we grant half victory, and this is more than fair for a non-sole winner. This win % of 70% (3.5 over 5) could have been 60% if you were not given the half tourney win.
3. This tie rarely happen, and with this half victory, your tourney win percentage is still far above the top rating you have achieved to-date. However, if you feel that this tie in SR will hurt your tourney rating, stay away from it, there are several other formats available, and if you wish to have more SE or DE please ask the HA in charge to do more.