It's not like he took the job from you, OP. Are you serious?
It's good that you want help for the budding resentment you're starting to feel. That just means your head isn't too far up your ass just yet. So, kudos for you to making this post.
On the other hand
but he’s made it clear that he doesn’t care how much the position should belong to me, he’s going to go after it anyway.
I want this so bad that and if Greg gets the position over me, I’ll be crushed
Are you absolutely kidding me?
A relationship is being a TEAM. It's not a contest. It's not a competition. It's not about one-upping the other person. If you think that way, you should probably be rethinking of being in the relationship.
Yes, you have all the certifications and the qualifications. However, there are OTHER things employers consider aside from those. Professionalism, soft-skills and other non-technical related skills to the job also weigh a lot. In fact, I have hired some people who did not start out so great at first, but since I saw they were committed and really worked hard, they got better. Eventually, they became our top performing employees.
I have also hired people who had all the right certifications and qualifications but turned out to be total dickbutts who took every single critique given to them "personally" because they didn't like "being judged" since they know their certifications "make them more than qualified" for the post "than all the other employees combined" (exact words from someone I just canned). Do you know where they are now? NOT WORKING FOR OUR COMPANY.
Another thing:
After told me about the call, I immediately expressed disappointment because I figured I would be the one to receive a call like that since they told me that I would definitely be considered for this coming season.
WHAT THE FUCK LADY
This is NOT the first thing a girlfriend should feel if something good happens to their boyfriend. The first thing you did when he told you about it WAS LOOK DOWN ON HIM AND COMPLAIN HOW YOU DESERVED IT MORE. Jeezus tapdancing Christmastree, lady. What the hell?!