romulus, You always ask such interesting questions. The verb "have to"....takes the bare form of an infinitive, not a gerund. (to) + be + present participle = present progressive infinitve to "be going" is the progressive infinitive of the verb "to go". I really have to be going now. The progressive infinitive is used to suggest that actions and events are/were/will be continuing around the time we are talking about. I really have to be going now. I really had to be going then. I will really have to be going by then. The difference in meaning is equivalent to the difference in meaning between I go....and....I am going.

hi,long time no see. i am back here! see u next day. hope you everything goes well.