Can anyone shed some light on what they think this might be

Can anyone shed some light on what they think this might be? It started a lump between my toe and has kept growing, now under the ball. It’s sometimes saw after I work out and it can sometimes be warm to the touch. My podiatrist gave me insoles saying I was flat footed and I was not wearing g supportive shoes but after about 8 months it’s just getting worse! Thanks all