Advice needed

Quick point I'd add: some (many?) bike shops will offer 'try before you buy' with a new saddle. It might be that they are tied to only one or two brands and put you through the fitting system it stipulates, but chances are high you'll come out with something half decent.

Firstly, get a saddle with a trough or hole down the middle. Most recent saddles copy this design and numb willies should be entirely avoidable.

Soreness on long rides while overweight is partly unavoidable but a good cycling posture helps. In the end you are crushing soft tissue between your seatbones and the seat, so when you are not used to it, it's going to be a bit tender but that goes with time. Resist adding padding and soft seats/covers. Extra padding simply deforms under weight and tends to crush your tender parts (whether male or female). A decent pair shorts with a good pad is essential, but I couldn't recommend a brand because different brands seem to fit different bodyu shapes better than others. You don't need to spend big money, DHB may be quite suitable for example. However, if the seams fall in the wrong place you can get some nasty chaffing and not much you can do but change to a different brand of shorts.

Saddles do come in differnt widths, generally a narrow fit for racing snakes and a wider fit for those built for comfort, not for speed. A decent bike shop should be able to estimate a suitable width (and no doubt there are online resources for saddle fit estimates).

 A road bike encourages a forward angle - I'm not one for a slammed stem, but something along the lines of a 45 degree forward angle to share the weight onto your arms - it also helps immensly with jarring - upright posture sends shocks up your spine - hence why hybrid bikes often offer a sprung seatpost.

In the first instance, I'm reluctant to recommend professional bike fits. A lot of their data is based on performance and the posture you want for semi-competitive cycling is different from an endurance, or even social cycling fit.

Final point is that tyres and frame have a big impact on bike comfort. Modern thinking is to run fatter tyres at lower pressure. If you've dusted off your old road bike and are running 23's and 110psi you want to think about fitting a larger tyre (frame may limit you there, so check before investing) and run your tyres softer. If you are carrying excess weight with inner-tubed tyres you need to work your way down gently as you risk snake bit punctures from potholes with softer tyres, but consider say 90 front 95 rear then try knocking another 5psi off if you aren't running on the rims through bumps. If you've bought a high performance bike, they can be rigid and unforgiving, longer distances are more suited to a sportive/endurance frame, something with a bit of give and is more forgiving.

I would say numbess should be entirely avoidable for anyone, with a suitable saddle and correct fit. It can be hard to diagnose/help over the internet so I would suggest seeing a local bike fitter, but for the saddle you want one that means you weight is being taken by your seatbones and the immediate vicinity, with no pressure on your perineum. Some bike shops/fitters have a range of saddles you can try; some have fancy machines that measure your sitbones to recommend a suitable saddle. Failing that, rather than buying new it might be prudent to buy saddles 2nd hand from eBay - if it doesn't suit you, you can sell it on (hopefully at no/minimal loss), and if you like it you can keep it or buy the same one new. 

A suitable fit and saddle will also certainly help general backside discomfort. So too would a good quality and well fitting pair of cycling shorts. However, I would caution that your body does take time to adapt too, and so a degree of discomfort may persist while your body adjusts. Indeed, even experienced cyclists often find that if they do an unusually long ride for them, they have some discomfort. 

Look at your saddle height, position (front to back, nearer or further away from the bars) and angle. Sounds from what you say as if your saddle is probably not tilted far enough forwards, that's definitely something that could cause all the issues you mention. There are masses of articles and videos available on YouTube to help you get it perfect for you, try that first before you think of buying a new one.

It might not be your saddle. Are you sure your bike fits you, saddle height, cleat positioning and handlebar height could all be factors. I know some will say spend on a bike fit but fitting videos from GCN, Road.cc etc should get you in the right area. If you're already there try a bike shop to see if they do tester saddles. Good luck!