I have to say that rehab CAN help. Least says (they) "give you the tools to use in staying sober". That is HUGE! Yes, it is not a "cure" but it can open a door to real sobriety.
Re: financial. Many rehabs have scholarships (look at the best-more grant money available from grateful (rich) sober folks. Some will work out a financial plan. There are halfway houses. Do check out all your options...