The past tense of see no light at the end of the tunnel is saw no light at the end of the tunnel.

The third-person singular simple present indicative form of see no light at the end of the tunnel is sees no light at the end of the tunnel.

The present participle of see no light at the end of the tunnel is seeing no light at the end of the tunnel.

The past participle of see no light at the end of the tunnel is seen no light at the end of the tunnel.