When you give your speech, you should immediately treat yourself. Give yourself a pat on the back, go out and get some ice cream, anything! But do not think about all the things that went wrong. No speech is perfect and you will never be 100% happy with your speech. You may get close, but something always could have been just a little bit better. Give yourself the time to be happy with your accomplishment. You can review it and do a postmortem the next day.
Speeches are meant to be a work in progress. Timing can be perfected. Physicality can be improved upon. But the point is you did it! You were successful! No matter how many mistakes happen, if you get a positive audience reaction, you did a great job. Take joy in it. Then improve it tomorrow.