I had a similar issue a while ago with a secondhand wheel, tightened up everything and it felt fine so on it went, turns out that previous owner had replaced the axle with a shorter one, result was the cone got mashed against the freehub locating bolt, it would not turn, replaced the axle, and the freehub locating bolt and have had no issues at all.
By the way power to you mate, keep those pedals turning ! Well when they can turn that is?!