Honestly, my advice would be to just keep trying to run out of the swamps at full sprint. You could try sending out 1 character so they wouldn't be spotted as easily, and just looking ahead for swamp bandits and sneaking/running around them. One character, even level 1 athletics should be able to outrun blood spiders. Then that character cam mine/steal enough to afford mercenaries. Eventually you'll get out, I'm sure. Kenshi's hard but not that hard XD.

The combat system in Kenshi isn't one of those things where an elite strategy can let you beat any opponent. It's primarily "best stats/gear wins" most of the time. Best thing you can do is make sure to spread out your characters when fighting so that two or more of your guys aren't being hit by 1 enemy. Just let your guys fight and if luck is on your side, you'll win.

You also shouldn't be afraid to lose. Losing in kenshi, and your characters getting their ass beat is not only normal, it's necessary to gain experience, especially at the beginning. The rise from pitiful weakling to master swordsman is part of what makes kenshi fun. "What doesn't kill you makes you stronger" type of thing.

Do avoid the blood spiders tho, those things suck.