I Seem To Have Hives On Skin (red Blotchy And

I seem to have hives on skin (red blotchy and often itchy ) mostly after getting out of bed in morning. I have gained over 20 pounds(125 to 150 )in last 4-5 months and mostly in my upper legs (thighs)
I am on whole 30 plan so not any sugar dairy grains for last 10 days.
anything natural I can be doing for this.? Even before this I have eaten pretty healthy (no fast food, eat not a lot of food in general (not hungry) and I work out three days per week at gym and distance walk 3 days per week .(2-4 miles)

I have had lots of testing heart, stomach (since lots of bloating/gas too) and blood work and all looks good.
I had my thyroid removed in 1996 and have been on levothyroxine .

any suggestions.?