After giving oral to a female i always have pain/lumps on the bit under my tongue that joins it to my mouth. is this normal??

Yes, as those tissues are being traumatized by the incisal edges of your lower anterior teeth.

Time to have an examination. Call your Dentist. May be from a short mandibular lingual frenum or from the trauma of the activity.

The frenulum of your tongue is getting injured against your teeth. Depending on how important the sex act is to you, your dentist could correct it surgically.