The second one's problem is that an adjective phrase "내가 여기 있을" precedes 계속하면 which expects a noun clause before it. So you might try fixing it by turning "내가 여기 있을" into a noun phrase. 1) 내가 여기 있음을 계속하면 2) 내가 여기 있는 것을 계속하면 These are grammatically correct, and #2 comes fairly close to natural sounding. But they are both much inferior to 내가 여기에서 계속 있으면, so no point in using either. They may be useful though in illustrating the grammar point.

내가 여기에서 계속 있으면 is right. 내가 여기있을 계속하면 doesn't make sense.