Billy Hunt's penalty in the dying seconds salvaged a point for nine-man Brightlingsea Regent as it ended 2-2 at Woodside Road.
Aaron Condon fired the visitors ahead on their first ever visit to Worthing but goals from George Barker and substitute Sam Rents in the space of seven minutes turned things around.
Brightlingsea's James Love and Josh Gould were both shown red cards minutes from the end following a melee but the visitors still managed to find a late leveller.
Substitute Danny Barker fouled Condon in the area and Hunt fired the penalty past Lucas Covolan.
A final day draw saw Worthing end the season 16th in the table and meant they were unable to better last season's finish of 14th.
Hinshelwood took a number of positives from the turnaround this season but felt Brightlingsea's late leveller dampened things a little.
He said: "I made the squad aware of how proud and pleased I have been with their efforts since I've come in. We know there is still plenty to work on and this was another game where we let things slip late on.
"A number of times this season we've been in a winning position but thrown it away in the closing stages. That could well be the difference between us sitting comfortably in mid-table next season or really pushing on for promotion, which is where myself and the club want to be."
Hinshelwood is set to sit down for discussions with every squad member over the course of this week as he looks ahead to his first full season in charge since returning to Woodside Road.
Worthing were roared on by 1,060 supporters in their final game of the season and ended the campaign with the third highest home average attendance in the division, behind only champions Billericay Town and runners-up Dulwich Hamlet.
Hinshelwood knows that support will be matched - if not bettered next season - and is targeting a push for National League South.
He added: "Worthing is a big club at this level and we want to be pushing to make the step up into the National League South.
"We're not going to be stupid and start throwing ridiculous sums at it, I don't believe that is the right way to go about things.
"But with the fanbase we have here, the facilities and a number of other factors, I believe we can push on.
"Keeping the core of the squad together is important and, with the addition of a few new faces in the summer, we'll really be looking to kick on."
Goalkeeper Lucas Covolan scooped both the player of the season and Away Boys' player of the season following the draw with Brightlingsea Regent.
WORTHING: Covolan; Colbran, Racine, Young; Meekums, Edwards, Mott, Sparks; Starkey, G.Barker; Pope. Subs: Rents (Racine, 45), Newton (Mott, 63), D.Barker (Starkey, 81), Pamment, Sisimayi.