I also think this needs treating with a matter of urgency, to obtain an accurate diagnosis, and treatment.
From your profile - you are a 21 year old type 1 diabetic.
A small leg ulcer to me is about the size of the little finger nail. It appears as a raw, or punched-out, area.
Is it spontaneous or traumatic?
Firstly, I'm afraid, any smoking needs stopping - nicotine is a very potent vasoconstrictor.
Diabetes should be optimised (you will know more about that than me!)
Infection, needs treating if present, adequate (not low) dose, adequate length 1-2 weeks. Can be swabbed by Practice Nurse.
Diagnosis - is it venous or arterial - specialist Podiatrist; diabetologist/endocrinologist; vascular team; Tissue Viability Nurse.
Pressures need checking - ankle/brachial index. Doppler ultrasound to check blood flow. Ultimately may need angiogram.
Practice Nurse - very good with dressing/compression bandaging varicose ulcers, and ongoing care of arterial ulcers.
I must encourage you to be very assertive, and push hard to get these things done. I will confess, surreptitiously, that if you were my son, and any Health Professional was thwarting you in this endeavour ... Well you get the gist.
Good luck my friend, keep us updated. Struma