Hi and welcome
Separation anxiety can be the result of insecurities, low self esteem etc that results in you relying on your partner and what he provides in your relationship. Firstly look at the positives, that your relationship is close and at least that is something you should not be concerned about.
However, you need to develop strategies to expand your social scene and meet other people. This will distract you a lot and also have the added benefit of your partner not feeling like he has to worry about you.
Hobbies, sports, groups and clubs are all available in most places. It will take some courage but there is no easy way to meet others. Once the initial step is taken often it all falls into place. My wife is introverted but she went to a dancing group and loves it, also joined a sewing group in our tiny town even though she didnt sew a lot she taught herself to crochet blankets.
Passions come from within, think deeply about what activities you were good at as a child and explore them. EG I was good at model airplanes so took that up many years ago, I was able to distract myself at home building them and socially mixed with club members on weekends.
Finally, you could consider counseling to overcome your fears. Intrusive thoughts can affect many of us when we are insecure. Your partner might be missing you just as much but might not display it as much as you. But space for partners to breathe away from our company is a good thing ..."absence makes the heart grow fonder"...
Try thinking positive. Becoming a positive thinker is a life changing development.
TonyWK
