I think skeleton armor doesn't actually provide any armor, and may actually decrease health, as a trade off for giving you the ability to grapple.
Not, it's +3 armour, +10 defense, +3 move and the grapple hook.
The previous armour, carapace or something, gives +4 armour.
So it's rather annoying that the best armour I have is irrelevant against the might of the aliens. The same problem occured at the beginning with thin men: they were powerful enough to one-shot and accurate enough to hit almost every time.
I really wish you could choose the specialisation of your soldiers. I don't need 6 snipers when I have a single heavy, a single assault, and no support soldiers whatsoever left.
Research Archangel armor and equip all those snipers with the jumping genemod. Then send the one Assault running around the map while the squad sight snipers all go to high ground and snipe everything from everywhere when the Assault sees them.
The problem is I need better soldiers now. If i had time and money enough to equip them it wouldn't be such a problem, but i don't have laser sniper rifles yet or titan amour - skeleton is the best i have.
Sounds like you are nearing a potentially inevitable demise. It happens when you don't manage to keep getting the equipment/upgrades/resources you need.
In one game I missed several UFOs due to me not getting interceptors on continents with satellites in time, and I wasn't able to get carapace armor before the second terror mission due to a lack of materials, and my squad of my best soldiers got wiped.
All I had were some squaddie snipers and rookies, and most of them got wiped in the subsequent UFO landing because mutons are teleporting haxors who loved to teleport into the same room my squad was in. "Trying to take your time and use tactics so you're rookies and useless squaddie snipers don't all die? Suddenly mutons!" I couldn't get the resources from the UFOs, couldn't get better soldiers, and couldn't stop all the panicking countries from bailing out. Long story short, I lost. Nothing I could do about it but restart.
You don't
have to send your soldiers out if you don't want to, unless it's some story mission or something. Just be prepared to handle the resulting increase in panic. Try to spread the promotions around; take a rookie along on easier missions, like early UFO missions, let lesser promoted soldiers try to get a kill before your sniper guarantees a oneshot kill, stuff like that.
There's an XCOM thread in the other games section if you're interested.