I'd say try finding some kind soul who has a sewing machine and beg/plead them to sew on a reinforced patch. Glues might fail on you and won't give you any warning. Failing that you might try your local drycleaners or tailors. I'd think that if it was done properly and was on the outside of the hammock you'd be fine. (insert legal waiver here). Old style Hennessey's have that big entry hole on the bottoms and they managed to sew it well enough to ensure no tearing.
If you're a heavy guy though, you might just want to replace.