Mold behind bathtub surround
I wouldn't risk a patch job when it comes to a situation involving water that's under pressure. Your problem could QUICKLY get worst!
The best you can do now is to get a couple of estimates. AT least 2. Talk to friends and neighbors for recommendations. Visit the Plumbing Aisle at the Home Center and ask the folks there if they know anyone that would do your job for side work. Tell them you can't afford a business-pro. After you get your estimate from EACH Pro, ask if there's a way you can save $$$, perhaps doing the demolition (if any). Maybe you could do the caulking, whatever. Just make sure you do your HOMEWORK to find out how to do whatever YOU do, right. Again, water under pressure is a hazard.
My best to ya and hope this helps.
Jay J -Moderator
PS: God BLess America!