I am greatly indebted to you for the help you always give me. - ok, formal I am greatly indebted to you for all you have done for me. <-- also good, if formal. I truly appreciate all the help you give me. I so appreciate all the help you give me. I truly appreciate you always helping. Thanks awfully for always helping. - not at all formal Thanks awfully for your help. - not at all formal Thanks awfully for all your help. - not at all formal I'd never use "do" with "help" as you suggested. That is "do help" - nope. I truly appreciate all the helpful things you do. <-- ok.

I am greatly indebted to you for the help you always give me. - ok, formal I truly appreciate all the helpful things you do.

Can I say it? " I am greatly indebted to you for all you have done to me"

Thanks Ray and Travis 💖

Sounds too formal and not exactly natural. To be indebted to someone implies a very meaning of owing and not something we would say typically. If you did want to say it like that: 1. I am greatly indebted to you for all the help you always do. If you wanted to sound natural: 1. I truly appreciate all the help you do