First and yes losing weight is a good way of starting your way back to full erections, also its a way of incressing the size of your p***s, they say for each 10 lbs you lose your p***s grows half and inch, this is because of the fat you are losing, so your on a good diet and keep to it is areal good thing, exercise is important, brisk walking and swimming are the 2 best thigs you can do.
And now your erections, try these, Tribulus will help your libido, help your testosterone and boost your energy, and take around 8 weeks to get up to full power, then there is Cayenne, Garlic and Ginger, these 3 will help your blood flow down below, Cayenne I take in tomato paste with olive oil to thin it down and take 3 small spoonfuls 3 times a day, Garlic chop the cloves from a whole head and put in olive oil and take as above, but on alternate days, and Ginger I take this in black tea with lemon and honey, but you can use green tea as well, youcan either use fresh Ginger, or dried powder, OK first you can google all these for more info and just add for ED on the end, try to let us know how you get on.
Good Luck
not necessarily. There are plenty of reasons why you may not be getting an erection.