Sarge 20 other girls. Make them feel good.
Stop seeing this girl you fancy for around 30 days. Cut off all kinds of communication with her. Build your PUA skills.
When so many girls want to make out with you, you'll lose a lot of that jealousy. It will be you who will be saying NO to their sexual advances and "Let's Just Be Friends" these girls. By then, it would be easier to get the girl that you fancy.
If you don't get her, move on. The girls you have sarged who want to make out with you will be more than happy to help you mend your broken heart.

_________________
Approach. Open. Escalate. Isolate
Here are my two essential rules on texting that will save you tons of time and money:
general-questions/topic137931.html