I had a similar problem. For driving the solution was to shift into first just before stopping. It was a pain to always hold in the clutch while stopped.

The cause was in the transmission. First gear has different dog teeth and brake bands. There in my transmission had been replaced and were for the wrong gear. I installed them as they were intended and it shifts correctly.

Your problem of not being able to get out of second makes me think you have a clutch problem. Either a broken tube in the tunnel or possibly the clutch fork at the transmission needs to be shimmed. Sounds like the clutch is not releasing fully.