Girlfriend:

Girl is absolutely wonderful, and she's the one. Been together 3 years, will be riding off into the sunset soon. She has been studying for her CPA and is wrapping up soon (24 months of intense studying). She is "into 3P if I'm really drunk". She is Chinese.

Situation:

Stress and studying for the CPA have completely stunted our sex life. In the past 24 months, maybe went through 3 boxes of condoms. We would be in the middle of it and then then dreaded "oh, I just remembered, when we're done with this I have to ask you something about tax deductions for other comprehensive income accounts". Unrelated, we have a roommate who just had sex for the first time at 22 and the hormones literally make it hard for me to sleep at night (I started having problems, then later found out she just lost the V). Lastly, GF has a friend who is DTF3P and will leave the country in August.

Problem:

It's me. While she's been distracted in bed, I've compensated the excitement by fantasizing about other women. Now I can't get the job done without it. It scares the shit out of me to think I'll spend the rest of my life faking it. I'll be on the sex offender list by 2030.

My efforts:

The only thought in my head is get this friend in bed with us to teach GF a thing or two about letting go and make me see her in a sexy situation (any specific/explicit advice on this 3P?). Her and I have discussed everything here except the "Problem" section, she has no feedback.

Do not do a threesome. It will ruin your relationship. Your GF WILL become jealous and insecure, and the relationship will go down the shitter.

First things first: your relationship is not wonderful, there is a significant problem that should be addressed, and a threesome is definitely not the solution. I think that your analysis is not completely honest, and that this distorts your idea of the problem. If you were to ask me, I discern two problems:
1. You do not enjoy sex with your girlfriend.
2. Your girlfriend does not enjoy sex with you.

This is not indicative of a sex offender, which I'm sure you don't really believe either, but of not enjoying sex with your girlfriend. Are you still attracted to her? If not, perhaps it will come back once both of you enjoy sex again.

This is not indicative of her not being able to let go, this is indicative of her not enjoying it. Does she come every time you have sex? Did this change over time? If you are completely honest with yourself, are you good in bed? If not, perhaps you should put time and effort in improving.

Both these problems will not resolve themselves, and a bad sex life is like a bomb under your relationship. This problem will require effort to solve, and part of this effort is to have a serious (even if uncomfortable) talk about it. Tell her that you are not satisfied with your sex life, and that you have the impression that she is not either. Ask her what she thinks, and whether she has ideas about how the sex can be improved for her. Listen first, then tell her about what you want. Hopefully, this will lead to a better sex life and will prevent having to ride into the sunset on separate horses in separate directions.

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One of the most useful things you will ever learn about body language.

Thanks for your interest and feedback. To answer some questions.

Sex was always great until somewhere in the past two years when this test came into our relationship (plenty of videos to confirm). Two weeks ago she had finished the last test of the series, and we had sex three times that week. She was screaming, panting, and red chest when we were done. It's been over a year since I have seen any of those from her. On my end, she's still not doing it for me but it was progress.

Well the scores came back and she didn't pass, so we have at least 6 more months of this and I am AFC with no end in sight.

There's plenty of people out there that aren't getting satisfaction and are frustrated, and maybe I'm not the only fiend who senses and gets insomniatic from sex pheromones. What's different is I have a girlfriend that listens and tries new things and I still take her out on dates and buy her flowers.

We're looking for any advice or ideas to reduce stress, improve sex, increase attraction, etc. I need to lead here because it's simple not fair to give her any more stress.