help?! pimple on thigh/leg?!

does anyone reckon this is like a cyst or boil on my thigh? it was a little dot there for as long as i can remember and a couple of days ago it randomly got very sore and red, it got bigger and feels tight , but mostly just sore even hurts to walk..? ive tried putting Betadine antiseptic ointment on it but so far its just staying the same... idk its just very irritating and painful. photo isnt that good but in real life it looks quite red and firm. anyone know what it could be, or anything to help? (excuse the not freshly shaved legs, itll hurt this to shave😂)

?!?!