It was full of spiderwebs and stuff, but there didn't seem to be any other path, so I steeled myself and went in.
Literal
Spiderwebs [and-とか] lots was [but-けど], other [to-に] paths [also-も] not-existing seemed so resolve [object-を] deciding entered went.
蜘蛛の巣とか一杯だった ('it was full of spiderwebs and such') uses とか for casual listing. 他に道も無さそうだった ('there didn't seem to be any other path') uses ~そう (appearance). 意を決して (いをけっして, 'steeling one's resolve') is a literary set phrase. 入っていきました uses ~ていく for entering and moving deeper in. An adventure narrative with great atmosphere.