Hi buddy.
I had a relationship with a girl I loved. I had a similar problem, except the erection was fine but i couldnt finish it. The result was the same as yours - i kept thinking about it each time, i lost interest in the sex and a bad circle was started in my mind. Of course, she thought it had something to do with her (thats natural, you cant help it).
The nice part about this is, that as with any problem or pattern in your mind theres a solution or the direct opposite pattern you also are able to apply.
I believe your mind consist of two things you should consider in this situation:
1. Arguments: I experienced that my erection was gone. I upset her as i couldnt make a "home run". I panicked. etc.
2. Conclusion: I can't have sex with her.
The interesting part now, is that if i tell you to NOT think about a white rabbit - the white rabbit appears.. Our mind doesnt understand the term "not or without" as it is processesing information to lead us to goals.
Now, your brain is your tool - dont ever forget that. You should always be aware that you have complete control of it in the long run. Otherwise, you would waste your time. As i mention "the long run" it is because of the submissive processes that is also going on like: if you have the flu, you dont tell your body to send out the right chemical substances. This will be handled automatically, just like the way your breath, heartrate, intestines etc work.
So, what matters right now for you is the goal you have - what fills your thoughts. The automatical processes will follow when you lead, and you cant NOT lead.
Right now your goal, as you explained, is to NOT be afraid. Right?
Instead. Think about how good you are at panicking before or during sex. This is your resource to get to your goal. You just have to use that skill the other way around. You have to make your brain go "oh, it's sex time. Nice." instead of "oh no.. here we go".
I bet you have several reasons to panick before or during sex. These reasons were there to help you before, not anymore as they now annoy you.
Please write down your arguments as i tried to explain (what happens in the moment). Keep them for yourself. Nobody else should see them. The important thing here is to accept them, by yourself.
When done writing down your arguments please find your conclusion (what you think happens next time), as in my example above. This should be the effect of the triggers(arguments).
Now the arguments and the conclusion is your white rabbit. The stuff you dont want anymore.
Next, think about all the positive things you gain when you dont have this anymore. In my occasion i would think about all the lovely sex im going to have. The smile from my girl as she knows shes good enough in bed, and attractive. The mornings i wake up, having sex, satisfied and feeling like a king. etc. Whatever matters to you, but you better make it real and positive
Close your eyes and imagine these positive things. You have to FEEL it. Relate to it.Feel where in your body fx happiness is placed. For me, its in my stomach, sometimes my throat. The important thing here is to genuinely feel it. It's real, it's whats coming - be excited, be happy about whats coming.
Important: Imagine yourself with these positive factors 3 times in the future. First time could be next time youre being with your girl. Second time some months later, and last time far out in the future.
While imagining these 3 events, be sure to make it vivid. See yourself in the situation, with your own eyes. Everything is in colour, the smells are there, its more a film than a still picture. Perhaps theres a sound or some music. You feel something (warm, hard, cold, smooth, round etc). Make it REAL, FEEL it.
As long as you associate yourself with the situation your brain WILL create these patterns for you. Just like memory works; its far easier to remember a piece of smiling cabbage with legs running around in a HUGE bowl of glass: than just the words: cabbage, glass.
The reason to this: Tiny smiling cabbage with legs in a huge glass bowl is much more impressive, you feel more.
Summary:
1. Accept your arguments, find the conclusions.
2. Find the positive aspects you have as soon as you let this other pattern go.
3. Imagine how the new era is. Feel what this gives you. It should be like looking into the future.
You can do this several times, but usually i find that one time really does a difference if you take your time. This is a very good place to invest your energy. Life is more important than letting your brain gain the control.
Besides all of this. Your situation is very normal. This will be no problem for you. Youre gonna rock those sheets like theres now tomorrow
Good luck buddy!