After hysterectomy when having sex especially with partner or my own secretions I'm raw, blood red and feels like liquid fire has been poured inside.

S/p hysterectomy. if recent may be healing skin/infection, if > 6 weeks may be some infection but vaginal dryness as well especially if they removed ovaries. truy astroglide or estrogen creams ( do not use estrogen if had hysterectomy for cancer) f/u with doc and check for infection scarring, adhesions.
Ovaries? If your ovaries were removed then the decrease in estrogen levels can cause these symptoms. This can be treated with Vaginal estrogen. Best to see your doctor to be sure their is no other issue. Hope this helps. .
GYN. You need to be examined by your OB=GYN. If you started sexual relations too soon after pregnancy, this might be a cause; however you need to be checked for bleeding causes and/or infection and inflammation. Please call for appointment today and abstain sexually until seen and evaluated.
See Ob/GYn. You may need to follow with your gyn or pcp. Sounds like you may have a yeast infection and probably need to be examined since you have had surgery recently.