Advise on building our own pool

This is a great forum, because it seems to have a lot of people contributing who have got great energy DIY talent. This is the way my husband and I live, in country Victoria on a small acerage with horses and German Shepherd Dogs With a basic downsized life we are usually able to barter most living needs. With one exception however- a doctor broke my back in 1997 and I am colapsing in on myself(We do not have money from litigation because neither Andrew or I believe in avoiding a "social price" and making the community suffer). With height loss, I look like Wylie.E.Coyote after the Acme weight has fallen on his head! Our problem is that the only exercise I can do is to swim, because I cannot walk, so we need to build an indoor swimming pool. This may be a little difficult on bartered fruit and veg !. We can borrow some money from our friendly local bank, but the $30,000 - $35,000 we thought would be adequate doesn't come near to pool companies quotes. We areb prepared to do anything ourselves, Andrew (my husband) can put a structure over the pool , but the actual pool is a problem. Are there any creative people out there who have built their own pool and who are willing to share the experience.? Thanks