There is no such thing as trying to lose weight, you either do what is required or you do not.
It does not matter what your weight was, nor what it is. You begin where the scale says and you go forward..dont look back and commit to making a change.
If you really want to lose weight you have to drastically change your current choices. If you have ever watched those shows like My 600 LB Life, the advice is consistent and the results are up to the person.
About two years ago I wanted to drop 30 lbs, not that I needed to but I wanted to..get back to high school weight. I decided to start running. I had no past experience running outside a very small distance, small meaning like 1/3 mile. That was my start.
I see people out when I am running that are young, much older than me, heavy, thin whatever. It does not matter where you begin only what you do going forward.
To really lose weight you have to do activity that raises your heart rate and do it for a long enough period that you burn calories...do not fall into lazy routines or make excuses. If you want to swim to lose weight, that works, cycle, that works, running that works, aerobics that works...but you will not see results unless you BURN calories...and do so most every single day.
You need to find an activity that motivates you, that you can do 5-6 days a week and grow into...that you really burn calories and you are ok doing for a long period of time.
Second of course is diet. I suggest if you really want to lose weight, drastically change your diet...do not leg into it and take your time...go cold turkey and make a drastic change. On that 600 lb show the doctor recommends a daily calorie consumption of 1200 calories. That is a solid guide to live by and that means low low low carb, low calorie and high veggies/lean meats. It also means no aklie, no sugar drinks, no sweets and no excuses.
When I was dropping weight I would burn 3000 calories a day and eat in that 1200 to 1500 a day range. You can do the math and figure out how many calories is in a pound of fat, then you either consume less or burn more, or a combination of both.
That is all there is to it...really. What you do with the information is completely your choice. If you really worked hard you could be down to 190 in less than a year, it would take sacrifice and hard work, but of course you would expect that to be what it takes.