The symptoms you are having can be due to hyhothyroidism,fatigue,deprssion,weight gain. Other common causes are: stress,anxiety,depression. And yes,many of your symptoms can be due to side effects of zantac.
So the most probable cause seems to be are:stress,anxiety,depression or due to side effects of zantac. Its good that you had stopped it.
Now consult your doctor for the change/replacement of this medication.
Hope this helped.
Ranitidine is excreted principally in urine via glomerular filtration and tubular secretion. The majority of urinary excretion of ranitidine occurs within the first 6 hours after administration. Most likely this is due to mix of thyroid ,zantac and stress.