happy for you that you have experienced such positive experiences on retreat.It s normal and almost expected that we get in touch with or reconnect with old injuries,unhelpful tensions,or holding patterns from physical or emotional experiences in the past.So I would say that your experience is helpful and indeed when we plunge deeper into a yoga practice , realisations of these patterns comes to the surface of our awareness ,thus we can work in appropriate ways to free ourselves from these conditionings or lovingly accept them,according to our nature It seems that you are working with awareness and kindness towards yourself .
With regard to headstand,certainly as a teacher , and in the tradition I teach in ,you wouldnt be taught headstand unitil you had practiced for two years ,having said that there are a few people who have the awareness , control and understanding of the body
that im sure they would be safe not to wait that long.Also some schools introduce the headstand straight away but this wast my experience so cant make an imformed comment. For Shoulderstand I personnally would recommend with support but Im not diehard about it. ive practised both ways ,but if you do have shouder issues perhaps sort this out, opening and freeing the shoulders , but it sounds like youre being skillfull around this.Shoulderstand and headstand are important Asanas according to the wise . if I injured my neck I would hang upside down from rope with no pressure on neck.
Obviously I dont know your circumstances ,age, weight ,medical history,so everything comes with this understanding,
Where are you in goa? I used to volunteer at the International animal rescue centre ,long time back.There are some good yoga teachers in goa , no?
om shanti