shrink sql server database and reduce memory usage today

We are having problems in the last few days with our VPS server using a lot of memory. It is using 1.75GBs - 1.9GBs and sql server is using 800 - 900 MBs of that and [login to view URL] is using 100MBs. The backup of the entire sql server express database is 1.07GBs but there is only one database within it that is very large at 920MBs. I deleted 220,000 records from one of the tables yesterday and attempted to shrink the database but I'm not sure if it worked. It gave an error first time and then each other time I tried the window would appear for a second and then close. It didn't make any difference to the size of the backups and the memory usage is still the same so it mustn't have worked. We are getting a lot more '1.1 new session failed' messages since yesterday and when I restart the sql server memory reduces down to 960MBs and then once restarted returns to 1.75GBs within 15 mins. About 3 months ago I deleted a load of records and shrank the database and it has worked fine ever since until yesterday. Can somebody who specialises in this sort of thing give us an hour or two of your time to help sort it out please?