Sun squares are meant to boost your overall health, as for the spiritual one (SVAHA) and not something in particular other than your entire entity , it's more of an aid rather than a cure. Where as the physical one (NAMA) you could reinforce healing of body parts or even entire body, YET I would not recommend it for psychological healing as it does not RULE over your mind and emotions as lets say the Moon or Mercury does.
For a psychological healing working I'd recommend Lydia's Wunjio working (RUNES) for a period of 40 days or even up to 80 (if you need it). I've just finished an 80 one and I can assure you I'm many ties more stable then I was at the beginning.
However If you need an affirmation for the NAMA solar mantra I would give the one I use personally, you then choose if you like it or modify it:
''In the most positive and healthy manner for me the energies of the Sun are now completely and permanently empowering and regenerating me and my body''
I also reinforce it at the and with ''....regenerating me and my body in the most powerful and positive way for me''
I know it's basically a pleonasm as I'm repeating the same condition stated at the start , but I want to make sure I put a lot of stress on the ''POSITIVE AND HEALTHY MANNER FOR ME''.
The sun is a very powerful source of energy. Take in too much and you may fry yourself.