Was there a recent increase or decrease in you medications? Did you abruptly stopped medications?
There can be multiple reasons for giddiness of this kind, apart from the one i mentioned above, it could be ear problem as well since you mentioned that it increases in changing neck position
Modifications in your medications can be done till you get to consult your psychiatrist
Pls have adequate water ,and stand with support
Next Steps
Consult Psychiatrist ( if possible offline ) otherwise online for modification of medications
Physical checkup might be needed
You may even show a general physician till then if there is anyone nearby so that atleast a physical examination can be done