U should not be ignoring any kind of ulcer in your mouth.  Reasons for ulcers in mouth can range from as simple as nutritional deficiencies,to infection to grave as Cancer. Symptomatic treatments advised without proper discussion of the case can help u give the temporary relief but are detrimental in understanding the true resin for the ulcer. Oral Medicine specialist is the right specialist doctor to help u in such cases. 

If this is not reoccurring, then you need not worry. Till that time you can apply some ointments that can help you deal with this problem.

Don't worry, it will go off soon

How did it come do you remember? Since How many days?

It is difficult to give a proper diagnosis without examining it. Whether the ulcer is associated with any other mass underneath the tongue or is it associated with burning sensation too. Any particular food (hot or cold) that causes relief or aggravates the pain. How long is the ulcer from. Has it increased in size. A proper history of your ulcer is required. Just by looking at the picture you have given, it looks like an apthous ulcer(quite common and mostly caused due to improper brushing or stress)

Avoid spicy and hot items in diet. Apply Dologel-CT oinment.

This is an apthous ulcer so dont worry.

Nothing to worry Apply hexigel ointment 2-3 times a day Use hexidine mouthwash Take A to Z once a day for 10 days

Hello, No need to worry. You will need specific treatment only if you have a tendency of having ulcers every now and then. If it occurs sometimes then it's totally fine. Take Ointment- Mucopain (apply it 5- 10 min before having meals everytime in a day.) This will anaesthetise the place where you have ulcer so that you can eat properly. Take Ointment- Kenacort( apply it after having meals atleast 4 times in a day) This will heal your ulcer very fast. Kindly do not take water or food atlest half an hour after applying it.

Mouth wash: BETADINE gargle, after food, 2.5ml,  take raw in mouth,  hold for 2-3 minutes and spit out. Do not eat drink or rinse mouth for next half an hour. Use mouth wash once a day, for 7 days, followed by once in every 2 days,after meal. CNBC and Gumex or Dologel CT,apply locally,5 times/day,after food,not to swallow saliva during the ointment applied on gum,spit out after 3-4 minutes. And rinse mouth thoroughly. C.becosule forte,once a day for 15 days. C.limcee 500, twice a day, for 2 weeks. Maintain oral hygiene.