Before you left for 5 years, how good of a pilot were you? It sounds like you hadn't soloed yet, with only 15hrs of stick time. If that's the case, then I'm not surprised most of it has "gone away" for you. It's not uncommon for students to "forget" a lot even over a winter. In this case, you'll really do best by going ahead and working with an instructor for a bit.

On the other hand, if you were a competent pilot who had progressed to the point where you were flying on instinct and reflex, then you'll find it comes right back to you. I was away from the hobby for over 10 years. I got back in with a trainer, and went up on a buddy box for the first flight, just in case. So I didn't do the first takeoff. But it all came back that first flight, and I was doing basic acrobatics and such that first flight. It all came right back, no problems. I probibly didn't need the trainer, but it was still the right approach.