Hello !!
It must be really tough for you to go through such changes in your mood and behaviour.
What you are experiencing is definitely changes in mood, lot of negativity and lack of interest in daily activities and pleasure. These are some of the signs of mood disorder. You may have reasons and this can be reactive as in a response to some.negative life event. At times , it may be just endogenous or by itself without any specific reasons..whatever the case is, we need to address this. I request you to stay strong, concentrate on positives no matter how hard it is at the moment, follow a routine and stay along with people you like and seek support and do activities which you enjoy. As for the stiffness in your body and muscles, thus happens due to excessive crying and changes in metabolites in your body and
calcium changes too which is secondary to crying. These are muscle spasms and be rest assured at the moment they do not appear to be seizures or fits as you are completely aware of them. Remember : Always, keep the faith , hope is the only thing sometime we need to hold on too. This too shall pass. This is temporary. You need to consult and discuss this further and you may need medications after a detailed analysis. Hope this helps !!