You don't say what operating system you use. But if it's Windows, remote desktop is an option. But please, don't port forward it directly to the internet.
You need a router/modem/firewall that will allow you to tunnel safely into your home network and remote into your desktop as if you are on the same network.
One of these would do the trick:
https://store.netgate.com/pfSense/SG-1100.aspxI'm afraid there's some upfront cost involved - and you would need to put your existing ISP hub/router into modem mode as it will sit on the internet side of your the firewall. Then you will need a switch and a Wireless Access Point.
There are tutorials and guides to help you set it up, but to be quite honest, you will need either a lot of patience or some help.
That said, once it is setup, it will be as reliable as your internet connection and more secure than any after market router you can buy in PC World.