Is This Sacrifice Sound?

WHITE has just played 16.Bg2xd5 and offered a draw in Keith Gregory (175) - Spanton (168), Dorset open round four.

Should I accept the draw, attack with ...f4 or play on with some other move?

*****
*****
*****
*****
*****
*****
*****
*****
*****
16...f4? 17.Ra1? (½–½, 44 moves)
My idea in the event of 17.Bxf4 was to sac the exchange with 17...Rxf4? and follow up, after 18.gxf4, with 18...Qh4 19.Qd2 Bh3 20.Rfe1 Qg4+, but there is no mate after 21.Kh1.
The engines Stockfish10 and Komodo10 reckon White is better in the diagram position, so objectively I should have accepted the draw offer.