The other day when I switched into second gear and gave it throttle, the bike nearly died and my radio went off. The radio then came back on and the bike was fine. On that same ride a little later the radio would go off then come back on a few times. Tried it again a couple of days later and it almost died again when I switched into second gear and tried to throttle up. The bike is an 07 street glide

Look for a wire that is touching the shift mechanism. Probably grounds out shifting.

2nd gear is usually when most riders throttle up higher than other gears. I would guess that 2nd gear issue is more of irony than anything else. Check the wiring harness inside your fairing. My wife has a street glide and that bike is known for the inner support on the fairing to break resulting in a LOT of vibrations. That shaking could very easily loosen any wire. You said on the same ride the radio went out again-were you shifting again? If not, I would definitely suggest pulling the fairing and taking a look. If you have never done that then you might want to consider taking it in for service. Pulling your fairing is a bit of work and there are a lot of wires in there.
Good luck!