What to do about a cheating problem.?

I have manic depression. Im not incontroll at all rite now and i need to get to a doctors (im 14) and i cheated on my gf alot to start... but im honestly in love with her it dont sound it...and i made out with one of her friends when me and her were in a little fight but(still datin) and now she dont think anything we did ment anything and she dont think i love her she said were still dating tho... and i have cut 2 times on my left wrist.... and i took 3 aleive what should i do PLEASE HELP HOW I CAN PROVE HOW I LOVE HER!!!!!!!!!!!