Questions for Runners

Alright..so I started running recently for weight loss and discovered I enjoy it quite a bit. Ive worked my way from running a half mile or a mile 3 times a week to running for an hour(10-11 min/mile pace) 4 or 5 times a week. Im loving it but have hit a sort of plateau at 160 lbs and an hour of running.

Im really looking for advice on breaking through that one hour mark and overtraining. I feel like I may be overtraining. (The days I dont run I walk an hour or lift a bit.) Phone Post 3.0

I don't run but I believe sprinting is a good way to mix it up. Like sprint across a 50m space back and forth Phone Post 3.0

in. I can run for like 50 feet then I walk for 2 miles and jog the last 10 feet back to the house. I want to run. It looks refreshing as fuck but my lungs hate that shit. 

I'm running a marathon in April. Most I've ever run is about 5 miles.
In for tips/advise!! Phone Post 3.0

Ttt. I know theres a few bad ass distance runners here. Phone Post 3.0