Is your problem with one particular tooth?or it is generalised?if its with one specific tooth,then it must be having cavity, which u must get filled at the earliest from your dentist or just take an intraoral x ray then do the treatment as suggested by your x ray and your dentist

Going by the description that you have mentioned, it seems that you have calculus deposits On The Teeth which are causing gum inflammation and malodour. What you remove by tooth brushing is the soft layer of plaque but these deposits of Calculus cannot be removed by toothbrushing. Visiting a dentist for a clinical examination and planning for a session of teeth cleaning by a process called as scaling is the next recommended step for you. Also don't forget to clean your tongue using your toothbrush only after every time you brush your teeth. Regards.