Anxiety in relationships :(
First of all thanks for taking the time to share. Welcome to our forums, I hope you find some of our messages useful.
No I don't think you will always be like this. With mental illness, it is with us forever, but it can be managed well.
Maybe it is a good time to see your GP and talk about how you are feeling? Your GP might be able to refer a good counsellor or psychologist? Have you ever had a Mental Health Plan? I have had two of these so got 20 discounted sessions with a psychologist which helped both me and my relationship.
Have you told your partner about how you are feeling? He sounds like he is a wonderful person who cares about you so much.
What about your diet and exercise? I am currently managing my anxiety with regular exercise, fresh and healthy food (most of the time!), reading, yoga and time out with my family and friends.
When I was in the midst of my last anxiety depths, I was also doing things like acupuncture, meditation and mindfulness. Have you ever tried things like this?