The Lasses rescued a dramatic point on the road last Sunday despite being 2-0 down at the break, with half-time substitute Amy Andrews causing havoc in the box before firing home in the 92nd minute.
While United remain seventh and have no league game until March 2nd, Langley wants her players to take the draw as a positive and build momentum heading into a busy end of the season.
"Of course, we're disappointed," Langley admitted post-match. "But after a poor first-half display we showed good character to come and draw the game.
"In the first half we lacked movement behind their defence and I think we made it easy for Southampton. Everything was played in front of them, which made us quite predictable.
"We can't sit and sulk about only picking up a point; we've got to keep going and build from it. We know it's a tight league, and we're just six points off top spot with a game in hand."
It was an inspired triple change at half time that helped swing the tide in United's favour at St. Mary's, with Andrews, Rachel Furness and new signing Emily Murphy getting 45 minutes under their belt.
Langley acknowledged that the game needed some fresh legs and praised Murphy and Andrews in particular for their impact on the match - and their role in extending the club's run of four games without a defeat.
"We wanted to freshen things up and bring some new ideas to the game, and I think all three of the girls did well when they came on," she added.
"I think that Emily looked really bright on her debut, so I was delighted by what I saw from her both in and out of possession, and she was involved in the first goal, which was one of the best goals I've ever seen us score.
"I'm delighted for Amy because she works so hard on the pitch and in training. She's a top girl and a great person to have in the squad and is an incredibly ambitious player."
United's boss was over the moon to see Birmingham-born Andrews get on the scoresheet for the fourth time this season when she popped up in the right area on Sunday.
In pre-season, Andrews got her first goal at St. James' Park against AC Milan Women in the Sela Cup, and Langley is keen to see her number 17 return to top goalscoring form in the final stretch of the campaign.
"Amy had a load of confidence in pre-season, and everything she touched was finding the back of the net; she's got speed to burn and a great finishing ability to accompany that," said Langley.
"We all know that strikers go through dry periods throughout their careers, but hopefully this can be the start of a good run for her."
Tickets are on sale here for next month's Tyne-Wear derby at St. James' Park against Sunderland Women.
