1) Practicalities -
If you are not wound up by the children, the dog won't be either, so work on your own situation. Meanwhile put a bed for the dog in a quieter part of the house and encourage him to go to it.
Get earphones that plug into your radio, so that you can listen to it and not the noise. If it doesn't have somewhere to plug them in, buy another that does.You can get small radios with earphones, that clip onto your clothes, or sit in your pocket, quite cheaply. And is there an earphone point on your TV?
Put up a fine net curtain at your front window so that the children can't see whether you are in there where they can annoy you, and you can't see whether they are there trying to peer in. Avoid looking out and glowering at them - it justs makes it fun for them to be cheeky.
Plant something attractive but prickly along the front fence to scratch them if they lean too far over it.
2) Adjust your relationship with them and with their parents. This may be difficult to do if it has gone downhill, but worth an effort. Get them on your side, not against you.
My aunt is over 80 and lives alone in an ex- LA house, surrounded by young families, some of them fairly "rough". She has no children and very strict rather oldfashioned ideas about religion, behaviour, litter and noise. You would expect her to be the target of unduly kids.
BUT the children all come and talk to her and the cats if she is in the front garden, telling her of their day. Sometimes she lets them help a bit, and tells them the names of plants and so on. She insists that they call her Mrs XXXX, not Peggy, and they do so, though new kids on the block often ask her what her first name is (she won't tell them)
She gets on well with their parents, because she always talks to them when she meets them as well, and doesn't complain about the children playing (unless they have been aggressive) None of them would allow their children to pester her, even the ones who are quick to fall out with each other over trifles, because they like and respect her. She has done bits of shopping for neighbours who couldn't get out. She has employed tradesmen neighbours for house maintenance that she couldn't manage herself (which are no longer done by the council since she bought the house)