Code Improvement Suggestions?

[Tool]

I am kind of in a bind and I don't know what I should do.

I have been working on an application at work for two and a half years now. This program constantly needs upgraded and new features. So far I have the program up to 40mb or so after installed. The problem I am having is I find it REALLY hard to develop new stuff,fix old stuff and speed it up.

I started on this job with absolutely NO vb.net background and little VB6 background. I had never even seen a database or knew how it worked. I have had to teach myself most of it via books/internet and some great help here. The new items I have to create at work are not very planned out, in the fact that as soon as my boss hears about it. I have to have it done in a little amount of time. And new things are added constantly, more often than not, before I finish an item I am currently working on.

I know a lot of my code has some minor to major flaws in it, but I rarely get time to go back and fix it, and it is becoming such a pain to work on this program. I don't even understand half of my old code (which im sure is a common problem as you advance in your knowledge).

One of the most major problems I am having, and don't know of any solution, is an EXTREMELY large context menu on the parent form. This menu must have EVERY link on the company's website (anywhere from 1500 to 3000 dont feel like counting). Almost daily new links are added to the website, and each time I compile I am supposed to go get all the new links to add to this menu. Every time I add a new menuitem, it takes anywhere from 2 to 5 minutes to go from code to design view on the parent form. Any ideas on how to fix that up, speed it up, or move it off the main/parent form?

Another problem I am having is my knowledge on threading is slim. I know how to create a thread no problem, but getting rid of it is my problem. What is the best way to go about disposing a thread? I have seen a few people say they set the thread to nothing... but would I do that in the function, or after I call the thread? (seems it would destroy it before the code is finished). I am not too sure on that.


Ugh... sorry I think I rambled on too much. Anyway if anyone feels like reading this novel post any comments would be appreciated. Thanks in advance



Edit: I have little OOP experience. I have been trying to teach myself how and when to use a class rather than a function/structure/form/etc... Would it be worth it to try and re-do this application from scratch (off hours) or a waste of time? It has 17+ forms, 40+ crystal reports, and 20 or so classes (not really an OOP class though, just a class to put most of the code for the forms)... I did that because it was taking a long time to switch from design/code view from all the controls on certain forms. Probably not great practice but I had to rig it somehow I guess. Some forms have 20k+ lines of code.