Dont undersell yourself, just because you dont have a flashy van dosent mean you shouldnt charge what your worth, still doing the same job
Agree 100%.
Sadly, people judge others by first impressions. A guy who is shabbly dressed or has unkept hair is less trusted than someone who is well presented. It doesn't make the person who is well presented a better person. You will be incorrectly judged, but because people think what they do doesn't mean they are right. Most won't know where you've been, what you have achieved so far in turning your life around, and what you still want to achieve.
If you feel you have a disadvantage because of your weight, then perhaps you could raise your confidence levels by dressing in a business uniform. I wear a bib and brace which hides my weight a bit as they are black. An embossed teeshirt with your business name might give you a confidence boost.
Charge the going rate for a house, don't under price. I'm slower than most due to my age, but it doesn't mean that I can't charge the going rate because I'm slower. If your results are as good as anyone else, then charge that rate. Yes it may take you a little longer, but money isn't what its all about in the end.
Window cleaners tend to brag about how much they have earnt which can sometimes be very demotivating for others. How would you feel if you found out they hadn't actually made that amount of money. Some people are money driven, salemen tend to be like that. But how do you judge a good saleman, by the amount of money he earns? No, because he may only be in it for himself and not what his customers actually need. Sometimes they lie about the benefits just to get the sale.
Remember, job satisfaction comes from knowing you have done a good window clean. When you look at the result, pat yourself on the back, tell yourself how well you have done. Set your own standards - if they are higher than your customers expectations then they will always be happy.
As you have been doing this a while now, you are due a price increase, especially on those under-priced houses. Raise them a little bit each year if you can until they are market related. Your customers have seen that you have gone to a great deal of effort to keep their windows clean, so most won't mind a small increase. If you can clean 6 houses a day, an increase of a £1 each will give you an extra £6 a day or £30 per week for the same effort.
Remember to ask your happy customers for referrals. That makes it easier to get a better price because you come recommended.